580,5 

FB 

V, 4:2-9 

1919-1929 

cop, 2 


FIELD  MUSEUM  OF  NATURAL  HISTORY. 

PUBLICATION  204. 
BOTANICAL  SERIES.  VOL.  IV,  No.  2. 


BY 


CHARLES  FREDERICK  MILLSPAUGH 

AND 
EARL  EDWARD  SHERFF. 


CHARLES  FREDERICK  MILLSPAUGH 
Curator,  Department  of  Botany. 


CHICAGO,  U.  S.  A. 
April,  1919. 


Dup. 


FIELD  MUSEUM  OF  NATURAL  HISTORY. 
t  \ 

PUBLICATION  204. 

BOTANICAL  SERIES.  VOL.  IV,  No.  2. 


REVISION  OF  THE  NORTH  AMERICAN 
SPECIES  OF  XANTHIUM 


BY 

CHARLES  FREDERICK  MILLSPAUGH 

AND          * 

EARL  EDWARD  SHERFF. 


CHARLBS  FREDERICK  MILLSPAUGH 
Curator,  Department  of  Botany. 


JUL 
UNIYERSJiy  Of 


CHICAGO,  U.  S.  A. 

Issued  April  30,  1919. 


PV~£- 

REVISION  OF  THE  NORTH  AMERICAN 
SPECIES  OF  XANTHIUM 


CHARLES  F.  MILLSPAUGH,  M.D.,  and  EARL  E.  SHERFF,  Ph.D 


The  monographic  study  of  the  genus  Xanthium  is  involved  in 
difficulties  not  only  as  to  bibliography  but  also  as  to  species  concept. 
Thanks  to  the  kind  and  hearty  co-operation  of  various  botanists,  we 
have  been  able  to  settle  very  satisfactorily  the  numerous  matters  of 
bibliography.  The  species  concept  in  Xanthium,  however,  must  long 
remain  a  perplexing  problem.  In  temperate  regions,  the  plants  do 
not  mature  their  fruits  sufficiently  for  exact  determination  until  after 
frost  comes  and  the  majority  of  collecting  botanists  have  ceased  their 
field-work.  This  renders  good  material  in  herbaria  scanty  in  quantity 
and  inadequate  in  quality.  Some  of  the  species  are  known  to  exhibit 
most  striking  variations  in  fruiting  characters, —  variations  that  with 
many  botanists  would  be  taken  to  represent  varieties  or  subspecies. 
In  fact,  several  of  the  more  pronounced  of  these  forms  have  been  made 
the  basis  of  new  species  by  certain  authors,  notably  Greene  (e.g., 
X.  acutum,  X.  affine,  X.  calif ornicum,  X.  glanduliferum) .  In  the  present 
monograph  the  writers  have  endeavored  to  be  neither  hasty  in  the 
proposal  of  new  specific  names  nor  radical  in  the  reduction  of  old 
names  to  synonomy.  The  taxonomic  treatment  has  been  made  to 
accord  as  strictly  as  possible  with  the  observed  data.  We  have  retained 
several  of  the  less  well  known  species  (e.g.,  X.  acerosum,  X.  cylindricum, 
X.  globosum,  species  that  with  some  botanists  might  be  reduced  to 
varietal  or  subspecific  rank),  because  we  have  felt  that  only  after  fur- 
ther field  observations  and  breeding  tests  can  satisfactory  conclusions 
as  to  their  true  status  be  reached. 

Many  of  the  numerous  references  in  literature  have  necessarily  been 
omitted  in  the  main  body  of  our  text:  for  a  large  number  of  these 
references  the  reader  is  directed  to  De  Candolle's  Prodromus 
(6:522-524.  1836)  and  to  Wallroth's  Monograph  of  Xanthium  (Beitr. 
Bot.  i":  229-244.  1844).  Since  the  publications  of  De  Candolle 
and  of  Wallroth,  several  other  more  or  less  extended  studies  of  the 
genus  have  been  made:  In  1893,  Rowlee  (Bull.  Torr.  Bot.  Club  20: 10), 
writing  upon  the  seedling  development  of  Xanthium,  noted  that  "both 


io      FIELD  MUSEUM  OF  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

achenes  in  a  single  head  frequently  germinate,  usually  not  at  the  same 
time  however,  so  the  seedlings  will  be  at  two  stages  of  growth."  In 
1895,  Arthur  (Proc.  Soc.  Prom.  Agricult.  Science  16:70-79)  remarked 
upon  the  inequality  in  size  between  the  two  achenes  in  the  burs  of 
Xanthium  and  the  delayed  germination  of  the  smaller  one.  Arthur 
stated  (loc,  tit.,  p.  77)  that  "the  bur  with  its  contents  is  the  physiological 
equivalent  of  an  achenium."  Later,  Masterman  (Ohio  Nat.  1:69-70. 
1901)  published  observations  upon  several  thousand  specimens  which 
showed  results  directly  opposite  to  those  of  Arthur  (thus,  of  3000  burs, 
2751  produced  two  plants  each,  at  the  same  time). 

In  1906,  Crocker  (Bot.  Gaz.  42:265-291),  writing  upon  delayed 
germination  of  seeds,  treated  of  the  physiological  conditions  of  delayed 
germination  of  Xanthium  seeds.  In  1908,  Bitter,  who  had  been  inspired 
by  the  early  observations  of  Lasch  (Bot.  Zeitung  14:409.  1856)  to 
undertake  careful  cultural  researches  upon  certain  species  of  Xanthium, 
was  able  to  describe  several  pronounced  races  of  X.  italicum  and  of 
X.  spinosum.  His  numerous  attempts  at  crossing  X.  spinosum  with 
species  of  the  Section  Euxanthium  had  been  in  vain.  Thus  he  states 
(Abhandl.  Nat.  Ver.  Bremen  19": 291.  1908):  "Bastarde  lassen  sich 
nach  meinen  Erfahrungen  zwischen  den  Euxanthien  leicht  erzielen, 
wenigstens  habe  ich  X.  macrocarpum  DC.  und  X.  italicum  erfolgreich 
mit  X.  strumarium  gekreuzt;  dagegen  waren  meine  vielfachen  Versuche, 
X.  spinosum  mit  Euxanthien  zu  kreuzen,  erfolglos." 

Somewhat  later  in  the  same  year,  Thellung  (Verhandl.  Bot.  Verein 
Brandenb.  50":  137-151;  see  also  Mitteil.  Bot.  Mus.  Univ.  Zurich  58: 
505-512.  1912)  published  a  very  comprehensive  survey  of  the  botanical 
literature  relating  to  X.  orientale  L.  and  X.  echinatum  Murr.  Thellung's 
concept  of  these  two  species  was  so  broad  that  his  treatment  of  them 
was  stretched  almost  into  monographic  proportions.  His  work  in  the 
herbarium  seems  to  have  been  far  less  extensive  than  his  work  in  the 
library.  We  are  not  able  otherwise  to  explain  many  of  his  numerous 
equations  of  species  with  each  other, —  species  which  in  several  in- 
stances are  so  strikingly  unlike  in  fruit  characters  that  we  are  entirely 
unable  to  accept  their  reduction  to  synonomy  by  Thellung. 

In  1911,  Shull  (Bot.  Gaz.  52:453-477)  published  his  investigations 
upon  the  oxygen  minimum  and  the  germination  of  Xanthium  seeds. 
Later,  in  1914,  the  same  writer  (Bot.  Gaz.  57  :  64-69)  presented  fur- 
ther data  obtained  along  these  lines.  Likewise  in  1914,  Dalbey  (Kansas 
Univ.  Science  Bull.  9  :  57-65  and  pis.  16-22)  enumerated  various 
anatomical  characters  of  X.  pennsylvanicum,  X.  americanum  [  =  X. 
chinense]  and  X.  globosum.  She  states  that  these  three  species  "pre- 
sent some  striking  external  characteristics,  while  in  their  anatomy  there 


APRIL,  1919.     XANTHIUM — MILLSPAUGH  AND  SHERFF.  n 

are  some  definite  but  minor  differences  which  might  prove  of  uncertain 
value  in  classification."  The  following  year  Fair  described  and  illus- 
trated the  origin  of  the  inflorescences  of  Xanthium  (Bot.  Gaz.  59: 
136-148  and  pi.  10.  1915).  Several  interesting  conclusions  are  stated 
by  Fair.  Among  these,  we  note  (he.  cit.,  p.  145)  that  the  "terminal 
heads  became  staminate,  because  the  vascular  supply  was  inadequate 
to  compensate  for  the  excessive  transpiration,  and  hence  the  pistils 
have  aborted";  also  that  "the  bur  is  a  modified  capitulum,  differing 
from  the  typical  head  of  Compositae  chiefly  in  the  two  depressions  in 
the  receptacle.  These  pits  originate  through  a  temporary  arrest  of 
development,  which  may  possibly  be  attributed  to  contact  with  the 
tips  of  the  recurved  involucral  bracts.  This  recurving  of  the  bracts 
may  be  the  result  of  limited  space  due  to  the  subtending  structures." 

Throughout  the  prosecution  of  our  own  study,  we  have  received  the 
most  generous  assistance  from  other  botanists,  both  in  America  and 
in  Europe.  It  is  with  a  sense  of  genuine  pleasure  that  we  express  our 
gratitude  for  such  help,  which  usually  consisted  either  in  loaning 
herbarium  material,  in  furnishing  photographic  reproductions  of  de- 
scriptions and  plates,  or  in  extending  to  us  various  herbarium  facilities. 
Chief  among  those  to  whom  we  are  thus  indebted  are  Prof.  August© 
Be*guinot,  Director,  R.  Orto  Botanico,  Padua;  Dr.  Ezra  Brainerd  of 
Middlebury,  Vermont;  Dr.  N.  L.  Britton,  Director  of  the  New  York 
Botanical  Garden;  Miss  Mary  A.  Day,  Librarian  of  Gray  Herbarium; 
the  late  M.  Casimir  De  Candolle,  of  Geneva;  Mrs.  Nellie  F.  Flynn  of 
Burlington,  Vermont;  Dr.  J.  M.  Greenman,  Curator  of  the  Herbarium 
of  the  Missouri  Botanical  Garden;  Dr.  H.  M.  Hall,  of  the  University 
of  California;  Professor  James  M.  Macoun,  of  the  Canadian  Geological 
Survey;  Mr.  Wm.  R.  Maxon,  Associate  Curator  of  the  United  States 
National  Herbarium;  Dr.  George  T.  Moore,  Director  of  the  Missouri 
Botanical  Garden;  Dr.  Julius  A.  Nieuwland,  of  the  University  of  Notre 
Dame  (in  charge  of  the  Greene  Herbarium) ;  Sir  David  Prain,  Director 
of  the  Royal  Botanical  Gardens  at  Kew;  Dr.  A.  B.  Rendle,  of  the 
British  Museum  of  Natural  History;  Dr.  B.  L.  Robinson,  Curator  of 
Gray  Herbarium;  Dr.  C.  A.  Shull  of  the  University  of  Kentucky,  and 
Miss  Ethelyn  M.  Tucker,  Librarian  of  the  Arnold  Arboretum. 

Upwards  of  two  hundred  photographs  were  made  of  the  more  im- 
portant specimens  examined  in  other  herbaria  during  the  progress  of 
the  work.  These,  together  with  full  data,  are  deposited  in  the  herb- 
arium of  this  Museum. 


12      FIELD  MUSEUM  OF  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

ABBREVIATIONS  USED  FOR  HERBARIA 

Hb.  Calif.  Herb.  University  of  California 

Hb.  Can.  Herb.  Canadian  Geological  Survey 

Hb.  Chi.  Herb.  University  of  Chicago 

Hb.  Field  Herb.  Field  Museum  of  Natural  History 

Hb.  Mo.  Herb.  Missouri  Botanical  Garden 

Hb.  N.  Y.  Herb.  New  York  Botanical  Garden 

Hb.  U.  S.  United  States  National  Herbarium 


Xanthium  (Tourn.)  Linn.  Sp.  PI.  987.    1753 
[Tourn.  Instit.  tab.  252,  1700.    Linn.  Gen.  PI.  424,  1754] 

Herbae  annuae,  ramosae,  crassae,  plerumque  scabridae  aut  spinosae, 
monoicae,  sporadicae.  Folia  alterna,  petiolis  tenuibus  petiolata,  plus 
minusve  lobata  aut  rarissime  inciso-divisa,  plerumque  punctis  resinosis 
parvis  numerosis  punctata.  Capitula  discoidea,  homogama.  Involucra 
mascula  summa,  subglobosa,  multiflora,  bracteis  liberis  i-3-seriatis; 
receptaculo  cylindraceo,  paleaceo;  corollis  tubulosis,  clavatis,  apice 
5-dentatis;  staminum  filamentis  monadelphis,  antheris  liberis,  con- 
niventibus,  basi  ecaudatis,  appendicibus  apicalibus  incurvato-mucro- 
natis;  stylo  simplici,  tenue,  ad  apicem  plus  minusve  dilatato;  achaenio 
rudimentario.  Involucra  feminea  gamophylla,  clausa  aut  rare  sub- 
clausa,  cylindrica  aut  ovoidea  aut  etiam  subglobosa,  hamato-aculeata 
aut  rarissime  simpliciter  aculeata,  ad  apicem  2-rostrato  (in  Sect.  II, 
Acanthoxanthio,  uno  aut  duobus  rostris  saepius  absentibus);  intus 
2-loculare;  corollis  absentibus;  styli  ramis  e  rostris  exsertis;  acheniis 
linearibus  aut  etiam  ovatis,  compressis,  plus  minusve  crassis,  ad  apicem 
tenuiter  rostratis,  levibus,  singulis  in  loculis  singulis  inaequalibus 
involucri  maturatis  et  manentibus. 

CLAVIS  GENERIS 

Folia  attenuata  utrinque;  axillis  spinis  tripartitis  munitis;  aculeis  ad 

apicem  cygneo-hamatis  i.  X.  spinosum 

Folia  cordata,  ovata  aut  subtriangulata;  axillis  inermibus;  aculeis  ad 

apicem  rectis  aut  simpliciter  hamosis: 

Fructus  maturi   plerumque  maximi,   aculeis  et  rostris   adjectis 

2.8-4  cm.  longi  et  2-3  cm.  lati: 
Aculei  plerumque  arcuati  et  corniformes,  subcrassi: 

Aculei  saepius  numerosi  et  conferti,  teretes     2 1 .  X.  campestre 
Aculei  plerumque  pauciores  et  remoti  aut  subremoti,  infimi 
ad  faciem  ventralem  canaliculati  19.  X.  oviforme 

Aculei  non  perspicue  arcuati  nisi  ad  apicem 

hamosum,  tenues  20.  X.  speciosum 

Fructus  maturi  minores: 
Aculei  pauci  et  remoti  (20-50) : 

Fructus  magni,  corpore  1.5—1.7  cm.  longo  et  6-7  mm.  lato; 
aculeis  8-10  mm.  longis  10.  X.  cenchroides 


APRIL,  1919.     XANTHIUM — MILLSPAUGH  AND  SHERFF.  13 

Fructus  minores : 

Fructi  maturi  subvirides  2.  X.  stramarium 

Fructi  maturi  plerumque  flavidi  aut  rubri: 
Fructus  corpus  anguste  cylindricum: 
Aculei  recti  ad  apicem  hamosi  8.  X.  leptocarpum 

Aculei  dimidio  supero  flexi  7.  X.  curvescens 

Fructus  corpus  ovatum  aut  oblongum: 
Aculei  cartilaginei,  crassi,  fructus  cor- 

pore  tire.  8  mm.  crasso  13.  X.  calvum 

Aculei  subtenues,  fructus  corpore  pler- 
umque 5-6  mm.  crasso  9.  X.  Wootoni 
Aculei  plures: 

Fructi  glabri  aut  subglabri: 
Fructus  corpus  plerumque  cylindricum: 

Folia  acute  lobata;  fructibus  venustis;  aculeis  tenuibus, 
2-5~3-5  mm-  longis  4.  X.  cylindricum 

Folia  subobtuse  lobata;  fructibus  crassioribus;  aculeis 
crassioribus  et  saepius  3.5-7  mm.  longis 

12.  X.  pennsylvanicum 
Fructus  corpus   plerumque  crasso-ovoideum  aut   subglo- 

bosum: 

Rostra  elongata  (6-9  mm.  longa);  species  mexicana  et 
austro-americana  15.  X.  australe 

Rostra  non  elongata  (3-4  mm.  longa); 

species  boralior  5.  X.  globosum 

Fructus  corpus  ovato-oblongum: 
Aculei  breves  (saepius  tire.  2  mm.  longi), 

basi  dilatati  14.  X.  palustre 

Aculei  longiores,  basi  non  perspicue  dilatati: 
Rostra  brevia  (circ.  2  mm.  longa),  crassa 

2.  X.  strumarium 

Rostra  longiora  (3-6  mm.  longa),  tenuiora: 
Aculei  conf erti,  arcuati : 

Quidam  aculei  ad  fructus  rostra  longissimi  (8-10 

mm.) ;  rostris  5-7  mm.  longis     n.  X.  inflexum 

Aculei  aequales  aut  subaequales  (4-6  mm.  longis)  ; 

rostris  3.5-5  mm.  longis  6.  X.  arcuatum 

Aculei  remotiores,  recti  3.  X.'  chinense 

Fructus  plus  minusve  setosi,  hispidi  aut  pilosi: 

Aculei  fructuum  maturorum  dense,  longe  et  molliter  fusco- 

pilosi  1 8.  X.  acerosum 

Aculei  fructuum  maturorum  setosi  aut  hispidi  sed  non  vere 

longo-  et  molli-pilosi : 

Fructus  8-1 2  mm.  longi ;  aculeis  tircum  2  mm.  longis  (specie 
maximam  partem  gerontogaea)        2.  X.  strumarium 
Fructus  et  aculei  longiores : 
Aculei  valde  hispidi: 

Corporis  latitude  quam  longitudo 

circ.  dimidio  minor  16.  X.  echinatum 

Corporis  latitude  etiam  minor  17.  X.  italicum 


14     FIELD  MUSEUM  OP  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

Aculei  non  valde  hispidi. 

Quidam  aculei  ad  fructus  rostra  longissimi   (8-10 
mm.)  ii.  X.  inflexum 

Aculei  aequales  aut  subaequales: 

Corpus  globoso-ovatum,  rostris  elongatis 

15.  X.  australe 

Corpus  plerumque  angustius,  rostris  non  perspicue 
elongatis  12.  X.  pennsylvanicum 

Sect.  I.  ACANTHOXANTHIUM  DC.  Prodr.  5  :  523.  1836;  Acanihoplia 
Wallr.,  Beitr.  Bot.  in  :  241.  1844;  Acanthoxanthtum  Fourr., 
pro  genere,  Ann.  Soc.  Linn.  Lyon.,  N.  Ser.  17  :  no.  1869.  Invol- 
ucri  fructigeri  rostrum  saepius  unicum  aut  nullum;  fructibus 
apice  conniventibus,  clausis;  spinis  validis  ad  basim  foliorum; 
foliis  numquam  cordatis  sed  basi  cuneatis. 

i.   XANTHIUM  SPINOSUM  Linn.  Sp.  PI.  987.     1753. 

Xanthium  xanthocarponWallr.  Beitr.  Bot.  in:24i.     1844. 

Acanthoxanihium  spinosum  Fourr.  Ann.  Soc.  Linn.  Lyon.,  N.  Ser. 

17  :  no.     1869. 

Caulis  pubescens,  ramosus,  erectus  aut  ascendens,  3-12  dm.  altus. 
Folia  lanceolata  aut  ovato-lanceolata,  petiolata,  utrinque  acuminata 
aut  acuta,  2-4-lobata  aut  supera  integra,  infra  et  ad  venas  supra 
canescentia,  petiolis  adjectis  4-12  cm.  longa,  axillis  spinis  gilvis  tri- 
partitis  usque  ad  2.5  cm.  longis  munita;  petiolis  0.5-2  cm.  longis. 
Fructus  (PI.  VII,  f.  i;  PI.  VIII,  ff.  1-3)  oblongo-cylindrici,  plerumque 
flavido-virides,  pubescentes;  rostris  tenuibus,  levibus,  acribus,  circ. 
3  mm.  longis,  plerumque  uno  et  saepe  etiam  duobus  absentibus;  aculeis 
distinctis  aut  remotis,  ex  apice  cygneo-curvato  in  hamum  inflexum 
quartam  aculei  partem  desinentibus.1 

DISTRIBUTION:  Now  generally  distributed  almost  throughout  the 
United  States;  found  also  in  South  America,  where  probably  native,2 
central  Europe,  "western  Asia,  southern  Africa  and  in  Australia." 

SPECIMENS  EXAMINED :3  NEW  YORK:  without  locality  or  date, 
M.  Ruger  (Hb.  Mo.  720720).  NEW  JERSEY:  Camden,  Aug.,  1878, 
Isaac  C.  Martindale  (Hb.  Mo.  720837).  DISTRICT  OF  COLUMBIA:  vicin. 
of  Washington,  waste  ground,  E.  S.  Steele  43  (Hb.  Mo.  85567  and 
85568).  VIRGINIA:  Bedford  County,  A.  H.  Curtis  3472  (Hb.  Mo. 
85569);  Wythe  County,  Reed  Creek,  at  base  of  lower  rocks,  July  23, 
1892,  John  K.  Small  (Hb.  Mo.  85570).  FLORIDA:  Apalachicola,  without 
date,  Dr.  A.  W.  Chapman  (Hb.  Mo.  783796).  ILLINOIS:  Mound  City, 

1  It  may  be  remarked  that  in  the  description  we  have  omitted  all  reference  to 
achene  characters.    As  the  characters  of  the  achene  can  not  be  described  satisfac- 
torily from  fruits  not  known  to  be  mature,  and  as  thoroughly  mature  fruits  have 
not,  in  all  species,  been  available  for  dissection,  it  has  been  deemed  best  to  omit 
these  characters  from  all  of  the  specific  descriptions. 

2  Cf.  Thellung,  Mitteil.  bot.  Mus.  Univ.  Zurich  58  :  505.    1912. 
*  Many  omitted  here  for  lack  of  space. 


APRIL,  1919.     XANTHIUM — MILLSPAUGH  AND  SHERFF.  15 

without  date,  George  Vasey  (Hb.  Field  13470).  KENTUCKY:  Bowling 
Green,  Oct.,  1899,  Sadie  F.  Price  (Hb.  Mo.  85573).  TENNESSEE: 
Knoxville,  vacant  lots,  July,  1893,  A.  Ruth  (Hb.  Mo.  720836).  MIS- 
SOURI: St.  Louis,  Oct.  23,  1893,  H.  Eggert  (Hb.  Mo.  85575,  720560  and 
720835).  TEXAS:  Handley,  Sept.  23,  1902,  /.  Reverchon  (Hb.  Mo. 
85580).  NEW  MEXICO:  near  Pecos,  Paul  C.  Standley  5150  (Hb.  Mo. 
85582;  Hb.  N.  Y.).  NEVADA:  Verdi,  Oct.,  1893,  C.  F.  Sonne  (Hb.  Calif. 
196334).  ARIZONA:  Prescott,  David  Griffiths  7344  (Hb.  Mo.  85583). 
VANCOUVER  ISLAND:  Nanaimo,  July  7, 1887,  John  Macoun  (Hb.  N.  Y.). 
WASHINGTON:  Walla  Walla,  July,  1898,  Savage,  Cameron  and  Lenocker 
(Hb.  Mo.  85584).  CALIFORNIA:  Los  Angeles,  Le  Roy  Abrams  4181 
(Hb.  Calif.  149138;  Hb.  Mo.  85589;  Hb.  N.  Y.);  Sherman,  Ernest 
Braunton  731  (Hb.  Calif.  54178);  vicin.  Mendocino,  H.  E.  Brown  919 
(Hb.  N.  Y.);  near  Yreka,  Geo.  D.  Butler  991  (Hb.  Calif.  163874); 
Colusa  County,  ].  Burtt  Davy  4277  (Hb.  Calif.  36807) ;  near  Durham, 
roadsides  and  fields,  A.  A.  Heller  12655  (Hb.  Mo.  802945);  San  Simeon 
Bay,  July  22,  1876,  Dr.  Edw.  Palmer  (Hb.  Mo.  85587);  Haywards, 
Nov.  14,  1893,  Ivar  Tidestrom  (Hb.  Calif.  36806);  Avalon,  Santa  Cata- 
lina  Isl.,  Aug.,  1902,  Blanch  Trask  (Hb.  N.  Y.). 

Wallroth  (loc.  cit.}  founded  his  Xanthium  xanthocarpon  upon  a 
specimen  by  Beyrich,  from  fields  between  Staunton  and  Charlottesville, 
Virginia.  The  distinctive  characters  tabulated  in  his  description  are 
entirely  too  inconstant,  however,  to  serve  in  distinguishing  the  species 
from  true  X.  spinosum  L.  Thus,  for  example,  Wallroth  described  the 
beaks  as  unequal,  the  larger  one  twice  stouter  than  the  prickles: 
("Rostris  inaequalibus,  majore  aculeis  duplo  validiore").  In  the 
nearly  two  hundred  specimens  of  X.  spinosum  which  we  have  examined, 
from  North  America,  we  have  seen  several  that  matched  Wallroth's 
description  in  these  and  other  respects  precisely.  Nevertheless  these 
specimens  were  but  slight  variations  from  the  more  common,  short- 
beaked  form  regarded  by  Wallroth  as  representing  the  true  Xanthium 
spinosum  L. 

Sect.  II.  EUXANTHIUM  DC.  Prodr.  5  :  523.  1836;  Anoplia  Waltr. 
Beitr.  Bot.  in:  229.  1844.  Involucri  fructigeri  rostra  apice  nunc 
recta  (Tribus  I.  Orthorrhyncha  Wallr.  loc.  cit.},  nunc  in  hamum 
varie  inflexum  desinentia  (Tribus  II.  Campylorrhyncha  Wallr., 
loc.  cit.},  nunc  hiatu  longitudinali  magis  minusve  contracto  reclusa 
vel  teretia,  nunc  transversim  fissa,  veluti  bivalvia;  caulibus  erectis 
saepius  purpureo-maculatis;  foliis  dentatis;  spinis  ad  basim  foliorum 
nullis. 


16      FIELD  MUSEUM  OF  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

2.   XANTHIUM  STRUMARIUM  Linn.  Sp.  PI.  987.    1753. 

Xanihium  priscorum  Wallr.  Beitr.  Bot.,  iu:  227.     1844.     (nom. 

semi-nudum.) 

Xanihium  antiquomm  Wallr.  loc.  cit.  229 
Xanihium  strumarium  L.  var.  antiquorum  (Wallr.)  Ball,  Jour. 

Linn.  Soc.  16  :  503.     1878. 
Xanihium  abyssinicum  Wallr.  loc.  cit.  230. 
Xanihium  discolor  Wallr.  loc.  cit.  232. 
Xanihium  Roxburghii  Wallr.  loc.  cit.  233. 
Xanihium  brevirostre  Wallr.  loc.  cit.  235. 

Caulis  subramosus,  pubescens*,  0.4-1.5  m.  altus.  Folia  triangulato- 
deltoidea  et  ad  basim  truncata  aut  subcordata,  3~5-lobata,  utrinque 
pilis  adpressis  strigosis  vestita  et  concoloria,  petiolis  adjectis  0.6-2.5  dm. 
longa;  petiolis  laminas  subaequantibus  aut  excedentibus.  'Fructuum 
(PI.  VII,  f.  2;  PI.  VIII,  ff.  4-8)  corpus  ovoideum,  aut  tumidum  et 
subglobosum,  plerumque  subviride,  pubescens,  0.8-1.4  cm.  longum; 
rostris  versus  apicem  rectis  aut  incurvatis,  1-2  mm.  longis,  saepius 
distantibus;  aculeis  rectis,  ad  apicem  hamosis,  supra  glabris,  infra  plus 
minusve  pubescentibus,  circ.  2  (rarius  3)  mm.  longis. 

DISTRIBUTION:  Adventive  in  Massachusetts  and  California;  native 
of  the  north-temperate  and  tropical  regions  of  the  Eastern  Hemisphere. 

SPECIMENS  EXAMINED:  MASSACHUSETTS:  Revere,  Crescent  Beach, 
Oct.  20,  igi2,M.L.Fernald  (Hb.  Gray).  CALIFORNIA:  Colorado  Desert, 
Cameron  Lake,  Mar.  28, 1901,  T.  S.  Brandegee  (Hb.  Calif.  131246). 

We  have  already  (Field  Mus.  Bot.  4:2.  1918)  noted  the  collection 
of  genuine  X.  strumarium  in  North  America,  by  Fernald,  in  1912.  It  is 
of  interest  to  note  that,  several  years  earlier,  this  species  was  collected 
in  the  extreme  southern  part  of  California,  by  Brandegee.  We  have  not 
seen  the  species  from  elsewhere  in  America.1 

In  1830  Rafinesque  listed  (Med.  Fl.  2  :  275)  "2  native  species 
Xanthium  crassum  and  undulatum  Raf.  mistaken  for  X.  strumarium 
and  orientale  by  authors."  Thus  Rafinesque  is  seen  to  have  realized, 
at  an  early  date,  that  the  common  forms  of  Xanthium  in  America  were 
not  referable  to  X.  strumarium  and  X.  orientale  (see  p.  26,  foot-note). 
Rafinesque's  two  names  appear  to  have  been  ignored,  or  indeed  over- 
looked, by  botanists  since  then.  But  obviously  these  names  can  be 
treated  only  as  nomina  nuda,  for  their  precise  application  to  definite 
American  species  is  impossible.  Characteristically,  in  this  connection, 
Rafinesque  fails  to  mention  his  own  Xanthium  maculatum,  described, 
in  detail,  from  the  eastern  United  States  eleven  years  before.  There 
exists,  in  Gray  Herbarium,  a  good  co-type  of  X.  abyssinicum  Wallr. 
(W.  Schimper  1343).  This  specimen  we  are  entirely  unable  to  separate 

_ 1  At  least  as  an  escaped  plant.  We  have  seen  good  fruiting  material  however, 
raised  by  Dr.  John  M.  Adams  at  Cincinnati,  Ohio,  in  1918,  from  seed  imported  with 
soy-beans  from  Manchuria  (specimen  in  Hb.  Ohio  Agr.  Exp.  Station). 


APRIL,  1919.     XANTHIUM — MILLSPAUGH  AND  SHERFF.  17 

from  X.  strumarium  L.;  in  the  same  herbarium  is  a  specimen  (Kotschyi 
iter  Nubicum  319,  ad  ripas  Nili  albi  prope  Chartum  in  provincia  Sennar, 
Mar.  4,  1840)  which  has  slightly  longer  and  more  numerous  prickles, 
these  more  hirsute  below  than  in  most  other  specimens.  This  is  the 
form  cited  by  Wallroth  for  his  X.  antiquorum.1  It  is  matched  very  well 
by  a  fine  specimen  in  the  Herbarium  of  Field  Museum  (Fred  S.  Meyers 
215,  waste  places,  Jaffa,  Aug.  2,  1902,  Hb.  Field  162920)  coming  from 
Palestine.  The  distinctions  emphasized  appear  to  us,  however,  too  slight 
and  inconstant  to  warrant  maintaining  X.  antiquorum  apart  from  X. 
strumarium.  Likewise,  after  examining  a  number  of  specimens  from 
India  (mainly  in  Hb.  Gray)  we  are  convinced  that  X.  discolor  Wallr., 
X.  Roocburghii  Wallr.  and  X.  brevirostre  Wallr.  are  merely  forms  of 
X.  strumarium  L.  (as  indeed  they  were  regarded  by  Hooker,  Fl.  Brit. 
Ind.,  3  :  303.  i88i).2 

3.   XANTHIUM  CHINENSE  Mill.  Gard.  Diet.  Edit.  VIII,  No.  4.    1768. 
Xanthium  chinense  Mill.  Abridg.  Gard.  Diet.  Edit.  VI,  No.  4. 

1771. 

Xanthium  occidentale  Bertol.  Lucubr.  Herb.  38.     1822. 
Xanthium  macrocarpum  var.  glabratum  DC.  Prodr.  5  :  523.    1836. 

ex.  descr. 

Xanthium  pungens  Wallr.  Beitr.  Bot.  in:  231.     1844. 
Xanthium  longirostre  Wallr.  loc.  cit.  237;  Britton  Fl.  Bermuda  384, 

f.  417.     1918. 
Xanthium  glabratum  Britt.  Man.  912.     1901.* 

1  Xanthium  priscorum  Wallr.  (loc.  cit.  227).  Wallroth  used  the  name  X.  priscorum 
in  his  clavis,  accompanying  it  with  a  short  diagnosis;  but  in  the  main  body  of  his  work 
and  also  in  the  introduction  (pp.  221  and  229)  he  had  changed  the  name  to  X.  anti- 
quorum.  His  retention  of  the  name  X.  priscorum  was  clearly  through  an  oversight. 
We  may  note  a  similar  error  in  regard  to  his  X.  eriocarpon  (which  is  referable  to 
X.  ambrosioides  Hook.  &  Arn.,  for  which  species  Wallroth  merely  made  a  new,  and 
in  his  opinion,  more  accurate  name;  we  have  seen  various  excellent  specimens  in 
Hb.  Gray  and  Hb.  N.  Y.).  Wallroth  at  first  (loc.  cit.  229)  advanced  this  species  in 
his  clavis  under  the  name  X.  leucocarpon,  with  a  short  diagnosis;  but  in  the  main 
body  of  his  work  (p.  242)  he  had  changed  the  name  to  X.  eriocarpon. 

1  Xanthium  inaequilaterum  DC.,  a  species  with  smaller  fruits  (5-6  mm.  long 
exclusive  of  the  beaks),  originally  described  from  material  collected  near  Buitenzorg, 
Java,  is  similar  to  X.  strumarium,  but  its  smaller  fruits  are  very  distinctive.  Several 
good  (topotypic)  fruiting  specimens  exist  in  Hb.  Gray  (Zollinger,  Batavia,  Java,  in 
1849;  Teysmann,  ex  horto  bogoriensi,  Buitenzorg,  Java,  in  1869).  These  are  re- 
markably uniform  and  appear  to  indicate  that  the  species  X.  inaequilaterum  DC. 
is  entirely  separate  from  X.  strumarium  L. 

A  number  of  other  species  of  Xanthium  have  been  described  from  the  Eastern 
Hemisphere  that  undoubtedly  are  mere  forms  of  X.  strumarium;  however,  as 
opportunity  has  been  lacking  to  examine  authentic  material,  their  names  have  been 
omitted  from  our  list  of  synonyms. 

lXanthium  canadense  of  Rowlee,  not  Miller,  Bull.  Torr.  Bot.  Club  20  :  10,  ff. 
g-m.  1893. 

f  Xanthium  carolinense  Dill,  ex  MacMillan,  Geol.  Nat.  Hist.  Surv.  Minn.  Bot. 
i  :  535-  1892.  We  have  not  seen  the  original  work  of  Dillenius,  cited  by 
MacMillan,  for  this  reference. 

Xanthium  strumarium  of  Millsp.  &  Chase,  Field  Mus.  Bot.  3  :  87,  f.     1904. 

Xanthium  strumarium  of  Britton  &  Brown,  111.  Fl.  3  :  298,  f.  3599.  1898.  See 
also  footnote,  p.  40. 


1 8      FIELD  MUSEUM  OF  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

Caulis  scaber,  0.3-1  (aut  etiam-2)  m.  altus.  Folia  late  triangulato- 
orbiculata,  acute  3-5-lobata,  subacute  dentata,  ad  basim  cordata  aut 
reniformia,  plerumque  submembranacea,  utrinque  concoloria  et  pilis 
setosis  adpressis  brevissimis  vestita,  petiolis  adjectis  1-3  dm.  longa, 
inferiora  interdum  2.5  dm.  lata,  petiolis  laminis  subaequantibus. 
Fructus  (PI.  VII,  f.  3;  PI.  VIII,  ff.  9-15)  ovoidei  aut  fusiformes,  calves- 
centes,  aequaliter  et  conformiter  aculeati,  fusco-virides  aut  rubescentes; 
corpore  sparsissime  brevi-pubescenti,  glanduloso,  0.9-1.5  cm.  longo 
(rarius  longiore);  rostris  rectis  aut  arcuatis,  infra  pubescentibus,  ad 
apicem  inflexis  aut  infirme  hamosis,  3-6  mm.  longis;  aculeis  glabratis 
aut  ad  basim  sparsim  glanduloso-pubescentibus,  rectis,  ad  apicem  hamo- 
sis, rostris  aequantibus. 

DISTRIBUTION:  Massachusetts,  Ontario  and  Nebraska,  to  Florida, 
Texas  and  California  (where  very  rare) ;  eastern  Mexico  and  throughout 
the  West  Indies. 

SPECIMENS  EXAMINED:1  MASSACHUSETTS :  Wayland,  Sept.  10,  1909, 
M.  L.  Fernald  (Hb.  Gray).  CONNECTICUT:  Goshen  County,  wet  ground, 
Sept.  18, 1905,  C.  H.  Bissell  (Hb.  Gray) ;  West  Hartford,  border  of  pond, 
Oct.  14,  1906,  idem  (Hb.  Gray).  NEW  YORK:  Long  Island,  Lakeville, 
waste  place,  Sept.  25,  1899,  /.  R.  Churchill  (Hb.  Gray)  Canton,  banks 
of  Grass  River,  Mrs.  Orra  Parker  Phelps  980  (Hb.  Gray) ;  Ogdensburg, 
along  banks  of  St.  Lawrence  River,  eadem  1215  (Hb.  Gray;  an  unique 
form  with  abnormally  large  fruits  having  bodies  1.9-2.4  cm.  long  and 
7.5-9.5  mm.  thick).  PENNSYLVANIA:  near  Philadelphia,  John  H.  Red- 
field  3475  (Hb.  Mo.  85397).  MARYLAND:  Plummer's  Island,  in  Potomac 
River,  near  Cabin  John,  Thomas  H.  Kearney  193  (Hb.  U.  S.  640356); 
shore  of  Chesapeake  Bay,  south  of  Havre  de  Grace,  George  H.  Shull  392 
(Hb.  Gray;  Hb.  Mo.  85399).  DISTRICT  or  COLUMBIA:  Washington, 
Charles  L.  Pollard  718  (Hb.  U.  S.  234642).  VIRGINIA:  Bedford  County, 
Oct.  10,  1871,  A.  H.  Curtiss  (Hb.  Gray);  Altavista,  waste  land,  Juliet 
Fauntleroy  677  (Hb.  U.  S.  754995).  NORTH  CAROLINA:  Buncombe 
County,  roadside  near  Black  Mountain,  Standley  and  Bollman  10301 
(Hb.  U.  S.  689122).  FLORIDA:  Lake  City,  anonymus  (Hb.  Fla.  Agricult. 
Coll.  no.  1279  in  Hb.  Field  234909);  Key  West,  sandy  places  near  the 
beach,  J.  K.  Small  3720  (Hb.  N.  Y.;  important  as  matching  precisely 
Greenman's  no.  47,  topotype  of  X.  chinense  from  vicinity  of  Vera  Cruz). 
ONTARIO:  Russell,  near  Nation  River,  July  28,  1911,  John  Macoun 
(Hb.  Mo.  719899).  MICHIGAN:  near  Port  Huron,  roadside  ditches, 
C.  K.  Dodge  43  (Hb.  Gray) ;  near  Port  Huron,  roadside  ditches,  idem  45 
(Hb.  Gray);  near  Port  Huron,  marshes,  idem  48  (Hb.  Gray).  KEN- 
TUCKY: Bowling  Green,  Aug.,  1899,  Sadie  F.  Price  (Hb.  Mo.  46001). 

1  For  lack  of  space  many  specimens  examined  must  be  omitted  here.  Our  citations 
are  complete,  however,  as  to  the  material  examined  from  Mexico  and  the  West 
Indies. 


APRIL,  1919.     XANTHIUM — MILLSPAUGH  AND  SHERFF.  19 

TENNESSEE:  vicin.  Smyrna,  Sept.  7,  1898,  H.  Eggert  (Hb.  Mo.  85404 
and  85405).  WEST  VIRGINIA:  Sweetsprings,  Steele  and  Steele  271 
(Hb.  Gray;  Hb.  Mo.  85401).  ALABAMA:  Auburn,  in  cultivated  fields, 
F.  S,  Earle  2202  (2  sheets  in  Hb.  N.  Y.);  Auburn,  Sept.  18,  1897,  Earle 
and  Baker  (Hb.  N.  Y.).  ILLINOIS:  St.  Clair  County,  Indian  Lake,  Sept. 
25, 1903,  H.  Eggert  (Hb.  Mo.  85420)  j1  MISSOURI:  Swan,  B.  F.  Bush  589 
(Hb.  Mo.  85411);  Courtney,  in  fields,  idem  871  (Hb.  Mo.  85407); 
Courtney,  in  bottoms,  idem  873  (Hb.  Mo.  85410) ;  Courtney,  in  bottoms, 
idem  7809  (Hb.  Mo.  809933) ;  St.  Louis,  cultivated  fields,  especially  in 
rich  land,  Aug.  1845,  Dr.  George  Engelmann  (Hb.  Mo.  85415  and  85416); 
St.  Louis,  riverbanks,  July,  1837,  Carl  A.  Geyer  (Hb.  Mo.  85414); 
Neck  City,  low  ground,  E.  J.  Palmer  1304  (Hb.  Mo.  85421  and  756630); 
Noel,  Butler  Creek,  gravel  bars,  idem  4220  (Hb.  Mo.  716541).  Kansas: 
Atchison  County,  in  fields,  A.  S.  Hitchcock  727  (Hb.  Gray;  Hb.  Mo. 
85424);  Riley  County,  low  ground,  /.  B.  Norton  261  (Hb.  Gray). 
NEBRASKA:  Red  Cloud,  .Rev.  J.  M.  Bates  5450  (Hb.  Gray).  OKLAHOMA: 
Sapulpa,  B.  F.  Bush  298  (Hb.  Mo.  85426).  ARKANSAS:  Fulton,  in  fields, 
B.  F.  Bush  965  (Hb.  Mo.  85422).  LOUISIANA:  Natchitoches,  wet 
ground,  E.  J.  Palmer  8727  (Hb.  Mo.  794561).  TEXAS:  Columbia,  in 
fields,  B.  F.  Bush  1348  (Hb.  Mo.  85428);  Dallas,  in  fields,  J.  Reverchon 
2591  (Hb.  Mo.  85431;  Hb.  N.  Y.).  CALIFORNIA:  Fort  Yuma,  Colorado 
River  bottoms,  5.  B.  Parish  8360  (Hb.  Gray; —  a  puzzling  specimen, 
in  some  respects  strongly  suggesting  X.  strumarium  L.,  which  has  been 
collected  west  of  here  by  Brandegee  at  Cameron  Lake.  See  X.  stru- 
marium L.).  MEXICO:  La  Laguna,  near  Vera  Cruz,  J.  M.  Greenman  47 
(Hb.  Field  189512;  Hb.  Gray).  BERMUDA  ISLS.:  Devonshire,  cultivated 
ground,  Brown  and  Britton  374  (Hb.  Field  203890;  Hb.  Gray);  waste 
grounds  near  Tucker's  Town,  iidem  1724,  (Hb.  U.  S.  758285).  BAHAMA 
ISLS.  :  Nassau,  waste  grounds,  Britton  and  Brace  383  (Hb.  Field  171815) ; 
Nassau,  Nov.,  1890,  A.  S.  Hitchcock  (Hb.  Field  174738).  CUBA:  Playa 
de  Cojimar,  on  coral  limestone  near  the  sea,  Mar.  16-26,  1906,  A.  S. 
Hitchcock  (Hb.  Field  235055);  Prov.  Havana,  Santiago,  plantations, 

1  In  the  same  herbarium  (No.  759001)  is  another  good  specimen,  by  Eggert,  from 
waste  places,  vicinity  of  East  St.  Louis,  Illinois,  Oct.  14,  1886;  on  the  same  sheet  with 
it  is  a  specimen,  closely  similar  in  habit  and  foliage,  but  in  fruits  approaching  X. 
pennsylvanicum  Wallr.  with  which  species  it  seems  to  be  a  hybrid.  This  second 
specimen  is  identical  with  two  others  of  the  same  date,  by  Eggert  (Hb.  Mo.  721197; 
Hb.  Gray).  A  fifth  specimen  of  the  same  date  and  locality,  likewise  by  Eggert 
(Hb.  Mo.  85526)  is  even  more  clearly  a  hybrid:  its  burs  are  fusiform,  dark  reddish- 
brown,  sparsely  and  inconspicuously  glandular-pubescent,  very  sparsely  aculeate, 
with  only  about  25-40  uncinate,  subglabrous  (unless  sparsely  hispid  at  the  base) 
prickles,  the  body  of  the  mature  burs  about  1.6  cm.  long  and  5.5  mm.  thick;  prickles 
and  beaks  4-6  mm.  long;  the  achenes  mostly  abortive.  The  burs  of  this  last  speci- 
men present  in  their  technical  characters  a  slight  resemblance  to  those  of  X.  Wootoni 
Cockll.  but  this  resemblance  is  very  superficial  and  disappears  upon  visual  comparison 
of  the  two  sorts. 


20     FIELD  MUSEUM  or  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

H.  A.  Van  Hermann  360  (Hb.  Field  172254);  without  locality,  in  1865, 
C.  Wright  (Hb.  Gray).  SANTO  DOMINGO:  Sanchez,  Rose,  Fitch  and  Rus- 
sell 4351  (Hb.  U.  S.  760483).  PORTO  Rico:  Vieques  Isl.,  Resolucion  to 
Punta  Arenas,  in  sand,  /.  A.  Shafer  2901  (Hb.  U.  S.  790346).  ST.  CROIX: 
Alfred  E.  Ricksecker  266  (Hb.  Field  70621).  TORTOLA:  Sea-cow  Bay, 
roadside,  Britton  and  Shafer  928  (Hb.  U.  S.  756709).  GUADELOUPE: 
Pfre  Duss  2816  (Hb.  Field  202726). 

Apparently  no  other  species  of  Xanthium  has  offered  heretofore  so 
baffling  a  problem  concerning  its  true  status  as  has  this  species.  It  has 
been  referred  at  various  times  to  such  species  as  X.  strumarium  L.,  X. 
canadense  Mill.  ,X .americanum  Walt.  etc.  From  X.  strumarium  L.  it  differs 
as  a  rule  very  distinctly  in  having  the  burs  larger,  smoother  and  greenish- 
brown  to  reddish  in  color,  not  mostly  yellowish-green;  furthermore,  the 
beaks  in  X.  chinense  are  longer.  X.  canadense,  as  we  indicate  else- 
where (p.  26,  foot-note)1  was  merely  X.  orientale  L.,  a  species  not  known 
authentically  in  America  and  differing  from  X.  chinense  in  having 
stouter,  more  coarsely  hooked  and  more  hispid  prickles  and  more 
arcuate  beaks. 

In  1768,  Philip  Miller  (Gard.  Diet.  Edit.  VIII,  no.  4)  advanced  a 
new  species  of  Xanthium  which  he  termed  X.  chinense.  He  described 
the  species  briefly,  "4.  Xanthium  (chinense)  caule  inermi  ramosa,  aculeis 
fructibus  erectis  longissimis.  China.  Xanthium  with  an  unarmed 
branching  stalk,  and  the  spines  of  the  fruit  very  long  and  upright." 
He  stated,  in  addition,  that  it  grew  "naturally  in  China  from  whence  he 
had  received  the  seeds."  But,  on  inspecting  his  description,  we  find  it 
to  portray  a  species  which  no  accounts  show  ever  to  have  been  collected 
in  China,  or  anywhere  else  in  the  Eastern  Hemisphere.  The  nearest 
approach  to  the  description,  as  concerns  the  Orient,  would  be  X. 
strumarium  L.  However,  not  even  the  Egyptian  form2  of  X.  stru- 
marium, the  form  with  spines  longer  than  usual  (2.5-3  mm.),  has  spines 
so  long  as  to  explain  or  justify  Miller's  use  of  the  word  "longissimis." 
It  is  very  likely  that  this  seemingly  insurmountable  discrepancy  between 
description  and  cited  habitat  has,  in  the  past,  entirely  deterred  botanists 

1  We  have  already  stated  (Field  Mus.  Bot.  4:  2.  1918)  that  the  name  canadense, 
advanced  by  Miller  in  the  eighth  edition  of  his  Gardener's  Dictionary,  was  equated 
in  the  ninth  (posthumous)  edition  with  X.  orientale  L.  We  may  note,  further,  that 
Miller  originally  cited  as  a  synonym  of  his  species  the  diagnosis  of  X.  orientale  L. 
and  gave  also  "X.  majus  canadense  H.  L.  635"  (Cf.  Thellung,'  Verhandl.  Bot.  Verein 
Brandenb.  50":  139.  1908).  But  Thellung  (loc.  cit.  138)  states  in  detail  and,  to  us 
very  convincingly,  the  evidence  that  this  "X.  majus  canadense  H.  L.  635"  is  merely 
the  X.  orientale  of  Linnaeus.  In  fact,  Linnaeus  himself  (Sp.  PL  Edit.  II:  1400. 
J763)  cited  "Xanthium  majus  canadense.  Herm.  lugdb.  635  "  as  the  second  synonym 
of  his  X.  orientale. 

J  X.  antiquorum  Wallr.,  found  also  in  Palestine.    Cf.  p.  17. 


APRIL,  1919.     XANTHIUM — MILLSPAUGH  AND  SHERFF.  21 

from  attacking  the  status  of  X.  chinense  in  a  more  than  cursory 
way.1 

Fortunately  for  our  purpose,  however,  there  appeared  in  1771,  the 
year  of  Philip  Miller's  death  (fide  Pritzel,  Thesaurus  218.  1872)  and 
three  years  subsequent  to  the  appearance  of  the  eighth  edition  of  The 
Gardener's  Dictionary,  an  Abridgement  of  Miller's  Gardener's  Dic- 
tionary, sixth  edition.2  In  this  abridgment,  Miller  introduced  X. 
chinense  from  his  Gardener's  Dictionary,  eighth  edition,  retaining  the 
same  peculiar  description3  but  omitting  the  word  China.  As  we  search 
his  supplementary  text,  we  find  a  most  interesting  statement:  "The 
fourth  sort  [X.  chinense]  was  discovered  by  the  late  Dr.  Houston  in 
the  year  1730,  growing  naturally  at  La  Vera  Cruz." 

Now  it  happens  that  in  1906,  Dr.  J.  M.  Greenman  spent  some  time 
collecting  in  the  neighborhood  of  Vera  Cruz  (Mexico)  for  Field  Museum 
and,  during  the  course  of  his  work,  collected  specimens  of  Xanthium 
(Greenman  47)  the  fruits  of  which  we  find  to  match  Miller's  description 
strikingly.  The  prickles  are  not  strongly  inbent,  as  in  the  X.  orientale  L. 
that  Miller  knew,  but  erect  ("erectis").  Nor  are  they  short,  as  in  the 
X.  strumarium  L.  known  to  Miller,  but,  by  comparison,  very  long 
("longissimis  "). 

It  appears  to  us  to  be  beyond  all  doubt  that  Miller  had  made  the 
acquaintance  of  this  species  in  the  prime  of  his  life,  during  the  period  of 
his  greater  literary  activity,  but  had  not  published  it; —  that  late  in  life 
when  seventy-seven  years  of  age  (fide  Pritzel,  Thesaurus  218.  1872), 
he  published  an  accurate  though  short  Latin  description  under  the 
name  X.  chinense,  thinking  that  to  it  belonged  various  Chinese  speci- 
mens sent  to  him; —  and  that  finally,  just  before  his  death,  he  realized 
his  mistake  in  having  referred  Chinese  specimens  to  the  species  and  so, 
with  a  view  to  clarity,  actually  stated  that  the  original  specimens  came 
from  Vera  Cruz. 

An  examination  of  the  Greenman  plants,  which  we  may  well  take  as 
representing  X.  chinense,  shows  them  to  be  the  same  species  that  grows 
very  commonly  throughout  the  West  Indies  and  which  Bertoloni 

1Wallroth  (Beitr.  Bot.  in:  223.  1844)  equated  X.  chinense  with  his  X.  dis- 
color, which  was  a  segregate  from  X.  stramarium  L.  But  Wallroth  expressly  stated 
for  his  X.  discolor  that  the  prickles  were  short  ("kurz  und  abstehend  eingebogene 
Stacheln")f  whence  it  appears  that  he  entirely  ignored  the  character  "longissimis" 
given  by  Miller. 

1  Regarding  the  extreme  rarity  of  this  work,  see  Thellung  (Verhandl.  Bot.  Verein 
Brandenb.  50°:  144.  1908).  We  have  been  fortunate  in  securing  excellent  copies 
of  the  pertinent  portions  from  the  volume  in  the  Library  of  the  Arnold  Arboretum, 
handwritten  for  us  by  the  Librarian,  Miss  Ethelyn  M.  Tucker. 

1  Miller  dropped  the  word  ramosa  after  caule  inermi  and  added  the  word  simplici- 
bus  after  erectis. 


22      FIELD  MUSEUM  OF  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

described  from  Santo  Domingo  in  1822,  under  the  name  X.  occidental.1 
Moreover  it  is  the  same  which  Wallroth,  in  1844,  named  somewhat 
provisionally  X.  longirostre.  Wallroth  very  clearly  voiced  his  hesitancy 
in  publishing  a  new  name,  but  he  had  not  seen  authentic  Santo  Domingo 
specimens  of  X.  occidental  with  which  to  match  his  X.  longirostre  mate- 
rial from  St.  Thomas  and  Haiti,  so  was  constrained  not  to  equate  the 
two  names. 

Specimens  from  the  West  Indies  vary  considerably  in  size  of  bur  and 
in  curvature  and  length  of  beaks.  Sometimes  the  prickles  are  slightly 
short-hispid  near  the  base, —  not  "simple"  as  described  by  Miller. 
The  Greenman  plants  exhibit  this  same  small  departure  from  the 
original  description.  Commonly  the  burs  are  rather  few,  large,  in 
color  greenish-brown.  A  character  frequently  observed,  especially  in 
the  West  Indian  material,  is  the  peculiar  appearance  of  many  of  the 
burs,  their  beaks  being  long,  not  widely  divergent,  somewhat  incurved 
and  suggesting  the  bill  of  a  bird;  this  character  is  present  on  several 
burs  of  the  Greenman  plants. 

Specimens  from  continental  North  America  usually  have  the  burs 
more  numerous,  smaller  and  more  or  less  reddish  in  color.  These  speci- 
mens harmonize  very  well  with  the  description  of  X.  pungens  Wallr., 
but  the  intergradations  between  the  continental  and  West  Indian  forms 
are  so  numerous  as  to  render  vain  all  our  attempts  at  separation.1 
Hence  we  are  compelled  to  regard  X.  pungens  as  merely  a  form  or  variety 
of  X.  chinense. 

In  not  a  few  cases,  X.  chinense  appears  from  herbarium  specimens,  to 
have  formed  hybrids  with  X.  pennsylvanicum  (cj.  p.  19,  foot-note).  At 
other  times  the  fruits,  varying  to  a  coarse,  more  elongate,  more  hispid 
type,  display  a  very  close  approach  to  those  of  the  same  species,  but 
without  suggestion  of  hybridity.  On  the  whole,  however,  the  two 
species  are  very  easily  distinguishable.8 

1  Raised  from  seed  sent  by  Bertero  from  Santo  Domingo.  "  Nux  oblonga,  medio 
ventricosa,  utrinque  attenuata,  muricata,  aculeis  raris,  subulatis,  uncinatis,  gra- 
cilibus,  apice  bi-trirostris,  rostris  convergentibus,  viridis,  vix  puberula."  (Bertol. 
Lucubr.  Herb.  38.  1822). 

*  Rydberg  (Dr.  Per  Axel),  also  Wiegand  (Dr.  Karl  M.)  each  of  whom  made  a 
somewhat  extended  preliminary  study  of  the  genus  Xanthium  and  then  postponed 
or  abandoned  the  investigation,  appear  to  have  met  with  the  same  result.  Thus  we 
note  on  a  sheet  of  typical  West  Indian  material  in  Gray  Herbarium  (Brown  and 
Britton  374,  Bermuda)  the  annotation  in  pencil  by  Rydberg,  "X.  americanum 
P.  A.  R."  and,  by  Wiegand,  "X.  pungens  Wallr.  K.  M.  W."  By  X.  americanum, 
Rydberg  meant,  as  his  other  herbarium  annotations  show,  the  X.  pungens  of  Wall- 
roth, which  had  of  late  been  referred  (by  Britton  and  Brown,  Illustr.  Fl.  Edit.  II. 
3:  346,  f.  4139)  to  the  enigmatic  X.  americanum  Walt. 

1Thellung  (Verhandl.  Bot.  Verein  Brandenb.  50°:  144.  1908)  equates  X. 
pennsylvanicum  Wallr.,  X.  occidental  Bertol.  and  various  other  names  categorically 
with  X.  echinatum  Murr.  The  chinense  of  Miller  he  resolves  into  two  parts,  regarding 
the  first  or  supposedly  Chinese  form  as  a  variety  of  X.  strumarium  L.  and  referring 


APRIL,  1919.     XANTHIUM — MILLSPAUGH  AND  SHERFF.  23 

4.  XANTHIUM  CYLINDRICUM  Millspaugh  and  Sherff,  Field  Mus.  Bot. 

4  :  4,  PL  3.     1918. 

Caulis  scabridus,  verisimiliter  0.5-1.5  m.  altus.  Folia  magna, 
quibusdam  foliis  Hibisci  militaris  Cav.  simillima,  subdeltoideo-ovata, 
trilobata  (et  fere  hastata)  aut  quinquelobata,  margine  dentata,  basi 
cordata  aut  subtruncata,  membranacea,  scabra  aut  tactui  etiam  fere 
levia,  setulis  adpressis  minutis  vestita,  petiolis  adjectis  1.3-2.5  dm. 
longa,  petiolis  laminis  subaequantibus.  Fructuum  (PL  VII.,  f.  4; 
PL  VIII.,  ff.  16-20)  corpus  cylindrico-fusiforme,  rubro-badium,  glandulis 
minutis  punctatum,  aliter  glabrum,  1.4-1.6  cm.  longum  et  4-5  mm. 
crassum;  rostris  arcuatis,  ad  apicem  hamosis,  glabratis,  4-5  mm.  longis; 
aculeis  tenuibus,  rubro-badiis,  ad  apicem  hamosis,  glabratis,  2.5-3.5  mm- 
longis. 

DISTRIBUTION:   North  Carolina. 

SPECIMENS  EXAMINED:  NORTH  CAROLINA:  Chimney  Rock  to  Hen- 
dersonville,  Oct.  3, 1901,  J.  K.  Small  and  A.  M.  Huger  (Hb.  Field  401312, 
type;  Hb.  N.  Y.,  cotype). 

When  this  species  was  originally  described,  there  was  no  question 
with  us  as  to  the  soundness  of  the  policy  pursued  by  certain  authors  of 
regarding  West  Indian  and  United  States  specimens  of  X.  chinense  as 
specifically  distinct.  But  since  then,  our  studies  have  convinced  us,  as 
stated  under  X.  chinense,  that  the  United  States  specimens  formerly 
referred  to  X.  americanum  (Auct.  amer.,  forsan  non  Walt.;  X.  stru- 
marium  Auct.  amer.  ex  parte,  non  L.;  X.  pungens  Wallr.)  represent 
merely  an  inconstant  race  or  variety  of  the  West  Indian  and  Mexican 
X.  chinense.  This  being  true,  there  arises  the  question  as  to  whether 
X.  cylindricum  likewise  may  not  indeed  prove  to  be  a  race  of  X.  chinense. 
So  far,  however,  we  have  been  unable  to  find  intermediate  specimens 
that  seemed  to  connect  adequately  with  X.  chinense.1  Hence  we  are 
constrained  to  reserve  judgment  in  the  matter  until  future  studies  shall 
have  thrown  more  light  upon  the  true  status  of  this  form. 

5.  Xanthium  globosum  Shull  sp.  nov.  (Cf.  Dalbey,  Kansas  Univ. 

Science  Bull.  9:  57.     1914;  Shull,  Bot.  Gaz.  59:  474-483.  1915.) 
Caulis  rubro-purpureus  aut  stramineus,  saepe  longitudinaliter  pur- 
pureo-punctatus,  3-10  dm.  altus;  ramis  demum  (in  speciminibus  robus- 

the  second  or  Mexican  form  to  X.  echinatum  Murr.  Clearly,  Thellung  was  totally 
lacking  as  to  a  proper  conception  of  X.  occidentale  (  =  X.  chinense),  a  species  that, 
under  various  names,  has  become  uniformly  recognized  in  recent  decades  by  promi- 
nent American  authors  as  a  valid  species.  Furthermore,  even  were  Thellung1  s  treat- 
ment correct  and  the  first  X.  chinense  (published  in  1768)  reduced  to  synonomy  with 
X.  strumarium  L.,  then  the  second  X.  chinense  (published  in  1771),  based  according 
to  Thellung  upon  a  different  plant  and  being  according  to  Thellung  an  entirely  different 
species,  would  become  valid  and  would  take  precedence  over  the  name  X.  echinatum 
Murr.  which  Thellung  maintains  (Cf.  Internat.  Rules  Bot.  Nomencl.  art.  50.  1906). 

1  We  have  found  two  specimens  of  X.  chinense  from  Missouri  (Webber,  roadsides, 
West  St.  Louis,  Oct.  14,  1890,  Hb.  Mo.  46000  and  85413)  that  show  small  leaves 
suggestive  in  form  and  color  of  the  larger  ones  on  X.  cylindricum. 


24      FIELD  MUSEUM  OF  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

tis)  plus  minusve  elongatis,  imis  etiam  i .  i  m.  longis.  Folia  non  perspicue 
crassa,  subdeltoidea,  tri-aut  quinquelobata  et  basi  cordata,  serrata, 
utrinque  setulis  adpressis  scabra,  petiolis  adjectis  0.7-2.3  dm.  longa, 
petiolis  laminis  subaequantibus.  Fructus  (PI.  VII.,  f.  5;  PL  VIII., 
ff.  21-23)  saepe  numerosi  (circum  1850  in  uno  specimine  observatis,  ex 
littera  Shullii) ;  corpore  late  ovoideo  aut  subgloboso,  vix  pubescenti  sed 
glandulis  minutissimis  numerosis  vestito,  0.9-1.1  cm.  longo  et  4.5-7  mm. 
crasso;  rostris  rectis  aut  non  ranter  arcuatis,  3-4  mm.  longis;  aculeis 
levibus  et  rectis  sed  ad  apicem  hamosis,  rostris  subaequantibus. 

DISTRIBUTION:   Missouri  and  Kansas. 

SPECIMENS  EXAMINED:  MISSOURI:  Randolph,  "a  very  common 
weed,"  Kenneth  K.  Mackenzie  387  (Hb.  Mo.  85408);  Jasper  County, 
La  Russel,  in  waste  places  along  railroads  and  in  fields,  Ernest  J.  Palmer 
1301  (Hb.  Mo.  46004  and  756629).  KANSAS:  Lawrence,  breeding 
grounds  of  Univ.  of  Kansas,  Sept.,  1913,  from  original  plants  obtained 
on  northern  edge  of  Wakarusa  flood  plain  about  0.5  km.  south  of 
Mount  Oread,  Charles  A.  Shull  (type  in  Hb.  Field  477325);  Lawrence, 
breeding  grounds  of  Univ.  of  Kansas,  Sept.,  1917,  idem  (Hb.  Field 
477328;  lineal  descendant  from  type  material);  Lawrence,  in  1917,  idem 
(Hb.  Field  477326;  burs  from  typical  plant  growing  wild);  Lawrence, 
breeding  grounds  of  Univ.  of  Kansas,  in  1917,  idem  (Hb.  Field  477327; 
burs  from  lineal  descendants  of  type  material). 

In  1915,  Shull  (loc.  tit.),  writing  upon  the  physiological  isolation  of 
types  in  Xanthium,  described  this  species.  Unfortunately,  however, 
no  Latin  diagnosis  was  published  (as  required  by  Article  36  of  the 
International  Rules  of  Nomenclature,  adopted  at  Vienna  in  1905), 
and  so  the  name  X.  globosum  must  be  regarded  as  having  been  hereto- 
fore unbinding  and  based  upon  a  foundation  very  insecure.  Early  in 
1918  we  took  the  liberty  of  writing  to  Dr.  Shull  regarding  the 
proper  publication  of  a  complete  taxonomic  description  in  Latin.  Dr. 
Shull  promptly  replied  in  a  most  cordial  manner  and  very  generously 
placed  at  our  disposal,  for  publication,  not  only  descriptive  notes  and 
photographs,  but  a  sheet  of  the  original  type  material,  also  other  sheets 
bearing  lineal  descendants  of  the  type  material  etc.  We  have  thought 
it  best  to  draw  up  our  description  rather  closely  from  these  sheets, 
hence  a  somewhat  narrower  description  has  been  presented  than  would 
have  been  the  case  had  we  included  the  variations  observed  in  the 
Missouri  specimens. 

A  study  of  ShulFs  several  specimens  shows  a  high  degree  of  uni- 
formity among  the  fruits.  The  species  is  probably  nearest  to  X.  chinense 
Mill.,  with  which  it  perhaps  intergrades,  or  hydridizes  at  times  if  left 
to  itself.  We  have  seen  specimens  from  Maryland  and  from  Iowa 
(G.  H.  Shull  392,  along  shore  of  Chesapeake  Bay,  south  of  Havre  de 


APRIL,  1919.     XANTHIUM — MILLSPAUGH  AND  SHERFF.  25 

Grace,  Maryland,  2  sheets  in  Hb.  Gray;  Hb.  Mo.  85399;  A.  S.  Hitch- 
cock, Iowa  City,  Iowa,  without  date,  Hb.  Mo.  85406)  which,  while 
referable  to  X.  chinense,  showed  a  strong  approach,  in  the  subglobose 
character  of  the  fruits,  to  X.  globosum. 

6.  XANTHIUM  ARCUATUM  Millspaugh  and  Sherff,  Field  Mus.  Bot.  4:  4. 

PI.  2.     1918. 

Caulis  superne  scabridus,  3-5  dm.  altus.  Folia  deltoideo-ovata 
3~5-lobata,  dentata,  basi  cordata  aut  subtruncata,  utrinque  setulis 
adpressis  scabra,  petiolis  adjectis  circ.  i  dm.  longa,  petiolis  laminis 
subaequantibus.  Fructuum  (PL  VII.,  f.  6;  PI.  VIII.,  ff.  24-26)  corpus 
anguste  ovatum,  aculeis  numerosis  armatum,  glandulis  multis  vestitum, 
demum  1.3-1.5  cm.  longum  et  5-6  mm.  crassum;  rostris  rectis  aut 
minime  arcuatis,  apice  hamosis,  non  pubescentibus  sed  infra  glandu- 
los  ferentibus,  3.5-5  mm.  longis;  aculeis  tenuibus,  maximam  partem 
arcuatis,  plus  minusve  rubro-purpureo  tinctis,  apice  hamosis,  infra 
glandulosis,  4-6  mm.  longis. 

DISTRIBUTION:   New  York. 

SPECIMENS  EXAMINED:  NEW  YORK:  Chemung  County,  river  shores 
and  low  places,  Oct.  n,  1896,  T.  F.  Lucy  (Hb.  Field  4953,  type). 

A  species  with  burs  intermediate  between  those  of  X.  chinense  and 
those  of  X.  pennsylvanicum,  but  having  prickles  more  arcuate.  Our 
failure  to  find,  in  various  herbaria,  additional  material  matching  the 
type  would  seem  to  indicate  that  either  X.  arcuatum  is  a  very  rare 
species  or  that  it  will  subsequently  prove  to  be  of  hybrid  origin. 

7.  Xanthium  curvescens  sp.  nov.   PI.  XI. 

Caulis  ramosus,  rubens,  scaber,  +3  dm.  altus.  Folia  deltoideo- 
cordata,  infirme  trilobata,  margine  dentata,  scabrida,  minute  reticulata, 
punctis  glandulosis  numerosis  minimis  punctata,  setulis  minutis  adpres- 
sis scabra,  non  crassa,  petiolis  adjectis  +i  dm.  longa,  petiolis  laminas 
subaequantibus.  Fructuum  (PI.  VII.,  f.  7;  PI.  VIII.,  ff.  27-29)  corpus 
anguste  cylindrico-fusiforme,  rubro-badium,  superne  sensim  angus- 
tatum  et  in  duo  rostra  distantia  productum,  exteriore  facie  30-50 
aculeis  armatum,  glabratum  sed  glandulis  minutis  numerosis  punctatum 
uti  bases  aculeorumet  rostrorum;  rostris  et  aculeis  rectis  solum  inferne, 
superne  valde  arcuato-uncinatis;  rostris  crassioribus  et  passim  paulo 
longioribus,  inferne  breviter  hispidis;  fructus  corpore  demum  1.3-1.6 
cm.  longo  et  3.5-5  mm.  crasso;  aculeis  3-6  mm.,  maximam  partem 
4.5-5.5  mm.  longis. 

DISTRIBUTION  :   Vermont. 

SPECIMENS  EXAMINED:  VERMONT:  Orwell,  Willard  W.  Eggleston 
1420  (type  in  Hb.  Gray). 

Because  of  its  strongly  bent  prickles  and  beaks,  we  were  disposed  at 
first  to  regard  this  species  as  a  form  of  the  European  X.  orientale  L. 
But  in  the  many  fruiting  specimens  of  X.  orientale  examined  from 


26      FIELD  MUSEUM  OF  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

Europe,  we  have  found  the  fruiting  involucres  to  be  not  only  consider- 
ably larger,  but  brownish  rather  than  reddish,  also  much  more  pubescent 
and  the  prickles  nearly  always  more  numerous.  In  its  narrow,  reddish, 
remotely  aculeate  fruits,  this  species  suggests  the  next,  X.  leptocarpum, 
the  type  of  which  was  collected  likewise  in  western  Vermont,  about 
three  years  earlier.  Indeed,  as  a  species,  it  seems  to  lie  just  half-way 
between  X.  orientate  and  X.  leptocarpum,  and  for  a  time  we  suspected 
it  of  being  a  hybrid  between  these  two  species.  But  the  apparent 
absence  of  true  X.  orientale  from  all  of  North  America1  would  seem  to 

1  X.  orientale  L.  Sp.  PI.  Edit.  II,  2:  1400  (ex  descript.  et  synon.;  excl.  loc.)  1763; 
L.  fil.  Dec.  II,  PI.  Rar.  Hort.  Upsal.  tab.  17.  1763;  Gaertner,  Fruct.  etSem.  PI.  2: 
tab.  164,  f.  2.  1791;  O.  Hoffmann,  Engler  and  Prantl  Naturl.  Pflanzenfamilien  4T: 
223,  f.  112.  1889;  X.  elatius  &  majus  Americanum  etc.,  Morison  PI.  Hist.  Univ. 
Oxon.  604,  sect.  15,  tab.  2,  f.  2.  1699;  X.  majus  canadense  Hermann,  Hort.  Lugd.- 
Batav.  635.  1687  (fide  Thellung);  Lappa  canadensis  minori  etc.,  Ray,  Hist.  PL  i: 
165.  1686  (fide  Thellung);  X.  canadense  Miller,  Gard.  Diet.  Edit.  VIII,  no.  2.  1768 
(cf.  Thellung,  Verhandl.  Bot.  Verein  Brandenb.  50°:  138.  1908;  O.  Hoffmann, 
Engler  and  Prantl.  Naturl.  Pflanzenfamilien  4V:  223.  1889);  X.  cuneatum  Moench, 
Meth.  Suppl.  300.  1802  (Moench  gave  an  entirely  inadequate  description, — 
"Xanthium,  cuneatum,  foliis  cuneiformibus  subtrilobis."  He  cited,  however, 
"Xanthium  orientale  Linnaei"  and  "Xanthium  majus  Americanum  fructu  spinulis 
aduncis  armato.  Morison  hist.  III.  p.  604,  icon.  Sect.  15  t.  2.  f.  2  "  for  his  two  syno- 
nyms); X.  echinatum  Wallroth,  Monogr.  Xanthium  in  Beitr.  Bot.  in:  239.  1844 
(Walpers  Repert.  Bot.  Syst.  6:  152.  1846)  non  Murray;  X.  macrocarpum  DC.,  Fl. 
Franc.  Suppl.  356.  1815. 

At  various  times  in  the  past,  Xanthium  orientale  L.  has  been  reported  as  occurring 
in  America.  Thus,  as  late  as  1913,  Britton  and  Brown  (Illustr.  Fl.  Edit.  II,  3:  346) 
stated  that  this  species  was  "naturalized  in  the  West  Indies."  But  an  examination 
of  various  specimens  of  Xanthium  from  the  West  Indies  (among  them  a  number  from 
the  Herbarium  of  the  New  York  Botanical  Garden,  and  determined  as  X.  orientale 
L.,  evidently  by  Dr.  Britton  himself),  fails  to  reveal  to  us  a  single  specimen  of  X. 
orientale.  Indeed,  all  so-called  specimens  of  X.  orientale  from  the  West  Indies 
that  we  have  seen  are  referable  to  X.  chinense  Miller  and  differ  very  markedly 
from  X.  orientale  L. 

Great  confusion  has  existed  heretofore  among  many  botanists  as  regards  the 
application  of  the  name  X.  orientale.  Linnaeus  himself  prefaced  his  original  descrip- 
tion with  three  synonyms  ("Xanthium  elatius  majus  americanum,  fructu  spinulis 
aduncis  munito.  Moris,  hist.  3.  p.  604.  s.  15.  t.  2.  f.  2.  Xanthium  majus  canadense. 
Herm.  lugdb.  635.  Lappa  canadensis  minori  congener  sed  procerior.  Raj.  hist.  165  ") 
and  with  the  statement,  "Habitat  in  China,  Japonia,  Zeylonia." 

If,  on  the  one  hand,  we  consistently  follow  the  custom  of  taking  earliest  cited 
synonyms  with  which  to  establish  our  concept  of  the  species,  there  can  arise  practi- 
cally no  doubt.  To  be  sure,  Morison's  figure  has  most  of  the  prickles  drawn  arcuate 
or  even  doubly  bent,  as  in  European  plants  of  X.  macrocarpum  DC.,  while  his 
American  material  must  surely  have  been  another  species  (the  Jamaica  plants,  for 
example,  undoubtedly  belonging  to  X.  chinense  Miller).  However,  Morison  definitely 

cited  the  Lappa  Canadensis material  of  the  Royal  Garden  of  Paris  as  a 

basis  for  his  species  ("2.  Elatius  &  majus  Americanum,  fructu  spinulis  aduncis 
armato.  Lappa  Canadensis  minori  congener  sed  procerior,  Hort.  Reg.  Par.  E  Vir- 
ginia, Carolina  &  Jamaicensi  Insula  accepimus.  V.  icon.,  tab.  aen.  2.").  And  (cf. 
Thellung,  Verhandl.  Bot.  Verein  Brandenb.  50":  138.  1908)  this  cited  material  of 
the  Paris  Garden  was  X.  macrocarpum  DC.,  for  in  the  very  year  following  the 
publication  of  Morison's  work,  Tournefort  (Instit.  1 :  439;  3:  tab.  252,  f.  M.  1700) 
cited  and  illustrated  this  "Lappa  canadensis "  material  and  his  illus- 
tration is  positively  of  the  X.  macrocarpum  DC.  Thus,  by  taking  in  turn  the  earliest 
cited  synonym  given  by  Linnaeus  and  by  Morison,  we  find  X.  orientale  L.  to  be  the 
plant  later  named  X.  macrocarpum  DC.  Thellung  (loc.  cit.)  has  come  to  the  same 
conclusion  and  he  cites,  furthermore,  very  strong  evidence  to  show  that  the  syno- 
nyms of  Hermann  and  Ray  likewise  belong  with  the  true  X.  macrocarpum  DC.,  i.e., 
DC.  FL  Franc.,  loc.  cit.  Later,  De  Candolle  (Prodr.  5:  523.  1836)  unfortunately 


APRIL,  1919.     XANTHIUM — MILLSPAUGH  AND  SHERFF.  37 

make  an  assumption  to  this  effect  purely  gratuitous.  Nor  do  we  feel 
inclined  to  regard  our  plant  as  an  anomalous  race  or  variety  of  X. 
leptocarpum,  since  the  arcuate  character  of  its  prickles  is  a  character 
that  holds  with  a  high  degree  of  uniformity  throughout  the  specimens 
of  the  corresponding  X.  orientale  of  Europe.1 

admitted  other,  specifically  different  material  to  his  X.  macrocarpum  and  so  it  is 
highly  important  that,  for  a  correct  concept  of  the  species,  recourse  be  had  only 
to  his  original  treatment  in  the  Flore  Francaise.  The  true  X.  macrocarpum  DC.  is 
a  plant  with  strongly  hooked  beaks  and  the  prickles  somewhat  subremote,  stoutish, 
tending  to  be  not  only  hooked  at  the  apex,  but  also  arcuate,  often  backwardly  then 
forwardly,  from  about  the  middle  upward. 

On  the  other  hand,  there  is  good  reason  for  discarding  the  Linnaean  synonyms 
entirely,  since  Linnaeus  himself  advanced  them  in  an  interrogative  way.  Thus,  at 
the  close  of  his  description,  he  asked  the  question,  "Synonyma  americanae  plantae 
an  differant?  "  Clearly,  Linnaeus  did  not  establish  his  species  upon  certain  synonyms 
and  then  doubtfully  refer  the  plant  under  observation  to  it;  but  he  did  base  his 
species  upon  the  plant  material  studied,  drawing  up  a  (for  that  period)  good  descrip- 
tion of  it,  and  then  to  this  species  the  interrogative  mark  and  the  wording  of  the 
question  show  that  he  doubtfully  referred  the  early  synonyms.  (This  point  is  indeed 
important,  for  in  case  a  discrepancy  did  exist  between  the  synonyms  and  the  plant 
of  the  description,  it  is  evident  that  Linnaeus  definitely  advanced  the  description 
and  not  the  synonomy.  But,  fortunately,  no  such  discrepancy  appears  to  have 
existed.)  —  Linnaeus'  doubts  were  evidently  inspired  by  the  fact  that  the  cited 
references,  although  agreeing  with  his  plant,  all  had  been  regarded  as  pertaining  to 
American  material.  If  we  note  his  own  citation  of  habitat,  we  find  that  he  regarded 
his  Xanthium  orientale  as  belonging  to  China,  Japan  and  Ceylon.  But,  it  happens 
that  his  description  is  illuminated  by  a  good,  clear  illustration  published  the  same 
year  (1763)  by  his  son,  from  plants  at  the  Garden  of  Upsala.  This  illustration  is 
very  decisive.  It  shows  the  Linnaean  plant  material  of  X.  orientale  to  have  been  a 
European  plant  (X.  macrocarpum  DC.),  a  plant  that  we  have  never  known  to  come 
from  the  Orient. 

In  1815,  De  Candolle  (loc.  cit.)  created  the  name  Xanthium  macrocarpum  as  a 
straight  synonym  for  the  Linnaean  description  of  Xanthium  orientale  and  for  the 
illustration  by  Linnaeus'  son.  He  was  impelled  to  create  the  new  name  X.  macro- 
carpum because  the  species  had  not  been  proved  to  grow  in  the  Orient  and  because, 
even  if  it  had,  the  name  orientale  would  be  hardly  appropriate,  since  the  plant  had 
been  collected  in  Languedoc:  "  La  description  de  Linni,  la  description  et  la  figure  de 
Linne"  fils  se  rapportent  parfaitement  a  notre  plante;  malgre"  cela  j'ai  cru  convenable 
de  ne  pas  lui  conseryer  le  nom  d' orientale,  i°.  parce  qu'il  n'est  pas  prouv6  que  cette 
plante  croisse  en  Chine,  au  Japon,  a  Ceylan;  2  .  parce  que  cette  habitation  supposed 
certaine,  le  nom  d'orientale  ne  serait  gu£re  convenable,  I'espSce  se  trouvant  en 
Languedoc.  OElle  a  e'tte'  trouve'e  dans  les  vignes  du  bas  Languedoc,  par  mademoiselle 
Lucie  Dunal."  (Among  various  authentic  French  specimens  of  this  species  we  have 
seen  an  old  one  from  De  Candolle  himself,  collected  in  this  same  region,  at  Mont- 
pelier.  It  is  in  the  Torrey  Herbarium,  now  at  the  Herbarium  of  the  New  York 
Botanical  Garden.) 

De  Candolle's  procedure  in  seeking  to  supplant  the  name  X.  orientale  with  the 
name  X.  macrocarpum  would  not,  of  course,  be  sanctioned  by  the  Vienna  Code 
(Internat.  Rules  Bot.  Nomencl.,  art.  50.  1906),  and  clearly  the  name  X.  orientale  L. 
must  be  retained. 

Our  search  through  botanical  literature  fails  to  show  any  true  X.  orientale  to 
have  been  collected  in  North  America  during  recent  times  (Cf.  Thellung.  loc.  cit.  141 : 
"Indessen  ist  das  echte  X.  orientale  aus  Nord-Amerika,  wenigstens  in  neurerer  Zeit, 
nicht  mit  Sicherheit  bekannt  geworden.") 

1  On  the  eve  of  publication,  we  have  received  an  admirable  set  of  specimens 
collected  for  us  by  Mrs.  Nellie  F.  Flynn  at  Burlington,  Vermont.  The  set  includes 
Xanthium  chinense,  X.  speciosum,  X.  italicum,  X.  leptocarpum  and  X.  curvescens. 
We  have  deposited  the  material  of  X.  curvescens  in  Hb.  Field,  nos.  481623,  481624, 
481625, 481626, 481627, 481630;  Hb.  Gray  ;Hb.  N.Y.  Its  burs  show  a  curious  simula- 
tion of  those  of  X.  orientale  L.,  but  are  much  smaller.  It  was  found  growing  with  X. 
italicum  and  X.  leptocarpum.  This  fact  naturally  leads  to  the  inquiry  as  to  whether 
or  not  X.  curvescens  may  ultimately  prove  to  be  of  hybrid  origin. 


28      FIELD  MUSEUM  OF  NATURAL  HISTORY  —  BOTANY,  VOL.  IV. 

8.  XANTHIUM  LEPTOCARPUM  Millspaugh  and  Sherff,  Field  Mus.  Bot. 

4:  3,  PL  I.     1918. 

Caulis  superne  scaber,  3-5  dm.  altus.  Folia  plus  minusve  deltoidea 
et  trilobata,  dentata,  basi  cordata  aut  subtruncata,  utrinque  setulis 
adpressis  scabrida,  petiolis  adjectis  7-19  cm.  longa,  petiolis  laminis 
subaequantibus.  Fructuum  (PI.  VII,  f.  8;  PL  VIII,  ff.  30-32)  corpus 
anguste  cylindrico-fusiforme,  badium,  superne  sensim  angustatum; 
exteriore  facie  et  basibus  aculeorum  et  rostrorum  pubescentibus, 
glandulosis;  18-40  aculeis  remotis,  2-3  aut  rare  -4  mm.  longis;  rostris 
distantibus,  arcuatis;  rostris  et  aculeis  ad  apicem  hamosis,  rostris 
crassioribus  et  paulo  longioribus;  fructus  corpore  1.3-1.6  cm.  longo, 
3.5-5  mm.  crasso. 

DISTRIBUTION  :   Vermont. 

SPECIMENS  EXAMINED:  VERMONT:  Burlington,  Sept.  12,  1896,  L.R. 
Jones  (Hb.  Field  430860,  type);  Shores  of  Lake  Champlain,  Oct.  30, 
1895,  and  Sept.  8,  1896,  Ezra  Brainerd  (Hb.  Gray). 

This  species  appears  most  closely  allied  with  X.  Wootoni  Cockll. 
Careful  comparisons,  however,  of  the  type  and  supplementary  material 
with  authentic  specimens  (cited  below)  of  X.  Wootoni  do  not  permit  us 
to  equate  the  two  species.  The  burs  of  X.  leptocarpum  are  uniformly 
much  narrower;  moreover,  they  have  about  twice  as  many  prickles  as 
do  those  of  X.  Wootoni  and  their  beaks  show  no  tendency  to  be  more  or 
less  cleft.1 

9.  XANTHIUM  WOOTONI  Cockerell  ex  De  Vries,  Sp.  and  Var.  140.    1905  ;* 

cf.  Proc.  Biol.  Soc.  Wash.  16:  187.     1903. 

X.  commune  var.  Wootoni  Cockerell,  ibid.,  p.  9.  1903. 

X.  Wootoni  Auct.  ex  Index  Kew.  Suppl.  3:  191.  1908. 

X.  oligacanihum  Piper,  Contrib.   U.   S.   Nat.  Herb,    n:   551. 


Caulis  erectus  aut  sese  extendens,  sparsim  scabrido-hispidus,  3-6  dm. 
altus.  Folia  reniformi-orbiculata  aut  deltoideo-cordata,  obscure  lobata, 
crenato-dentata,  setulis  minutis  adpressis  scabrida,  petiolis  adjectis 
0.8-1.5  dm.  longa,  petiolis  laminas  aequantibus  aut  paulo  excedentibus. 
Fructuum  (PL  VII,  f.  9;  PL  VIII,  ff.  33-36)  corpus  oblongum,  vel 
stramineum  vel  badium  vel  etiam  rubro-fuscum,  superne  sensim  angus- 

1  See  also  footnote  (p.  27)  under  X.  curvescens. 

2  See  also  Science,  New  Series,  42:   871.    1915. 

1  We  have  purposely  given  the  synonomy  as  fully  as  we  can.  Cockerell  originally 
proposed  the  plant  as  a  variety.  But,  in  accordance  with  their  entirely  unjustified 
method  of  indexing  varieties,  subspecies  etc.,  as  species,  the  Biological  Society  of 
Washington  indexed  the  plant  at  the  back  of  their  volume  as  a  species.  In  1905, 
De  Vries  (loc.  cit.)  first  stated  the  binomial  at  all  creditably  and  he  definitely  attrib- 
uted the  name  to  Cockerell.  As  the  retention  of  a  multitude  of  taxonpmic  binomials, 
each  accredited  merely  to  some  anonymous  author  (e.g.,  "Auct."  in  Index  Kew. 
loc.  cit.)  can  result  only  in  endless  confusion  in  the  future,  we  feel  ourselves  in  accord 
with  the  spirit  of  the  Vienna  Code  (Internat.  Rules  Bot.  Nomencl.,  art.  4:  2.  1906) 
in  taking  De  Vries'  book  as  the  place  of  valid  publication. 


APRIL,  1919.     XANTHIUM — MILLSPATJGH  AND  SHERFF.  29 

tatum  et  in  duo  (aut  rarius  tria)  rostra  distantia  productum,  12-30 
aculeis  (3.5-6  mm.  longis)  armatum,  molliter  glanduloso-pubescens  uti 
bases  aculeorum  et  rostrorum,  1.1-1.4  (rariter  1.6)  cm.  longum  et  5-6 
(-7,  fide  Piperi)  mm.  crassum;  rostris  rectis  aut  versus  apicem  incurva- 
tis,  saepe  hiantibus  et  achaenia  in  conspectu  ponentibus,  aculeos 
aequantibus;  aculeis  rectis  aut  subrectis  sed  ad  apicem  hamosis,  non 
pubescentibus  nisi  versus  basim. 

DISTRIBUTION  :   Massachusetts,  New  Mexico  and  Washington. 

SPECIMENS  EXAMINED:  MASSACHUSETTS:  South  Boston,  made  land, 
Oct.  4,  1909,  Walter  Deane  (2  sheets,  Hb.  Gray).  NEW  MEXICO:  Las 
Vegas,  T.  D.  A.  Cockerell  15  (author's  material  of  X.  commune  Wootoni 
Cockerell,  Hb.  N.  Y.);  Las  Vegas,  in  1902,  idem  (author's  material  of 
X.  commune  Wootoni  Cockerell,  Hb.  Gray).  WASHINGTON:  Waits- 
burg,  bars  of  streams,  Robt.  M.  Homer  B.  272  (Hb.  Gray) ;  Bolles,  in 
fields,  Sept.  18, 1893,  C.  V.  Piper  (Hb.  N.  Y.;  cotype  of  X.  oligacanihum 
Piper). 

Repeated  studies  upon  this  species  have  indicated  it  to  be  distinct 
and  worthy  of  specific  rank.  DeVries  (loc,  tit.}  found  that  the  seed  sent 
him  by  Cockerell  (who  was  the  first  to  pay  particular  attention  to  the 
plant)  produced,  when  planted  in  DeVries'  garden,  plants  true  to  type. 
Wooton  and  Standley  (Contrib.  U.  S.  Nat.  Herb.   19:   635.    1915), 
while  reluctantly  retaining  the  form  as  a  variety  of  Xanihium  commune 
Britton  (=X.  italicum  Moretti),  state  nevertheless  that  it  "seems 
distinct  enough  from  X.  commune  to  be  regarded  as  a  species.    It  cer- 
tainly is  more  easily  separable  from  that  than  are  most  of  the  eastern 
species  from  each  other.   .....  Ordinarily  the  two  plants  are  distinct 

enough."  Cockerell  himself  (Science,  New  Ser.  42:  871.  1915), 
although  at  first  inclined  to  regard  the  plant  as  a  variety,  finally,  as  a 
result  of  an  additional  observation  upon  X.  commune  and  also  in  view 
of  DeVries'  results,  stated,  "We  must  apparently  conclude  that  X. 
Wootoni  is  a  valid  species,  but  that  commune  from  time  to  time  varies 
or  mutates  to  a  virtually  identical  form."  And,  several  years  before, 
Piper  regarded  it  as  a  species.  He  stated  that  it  differed  "from  any 
other  American  species  in  the  small  size  of  the  fruit  and  the  relatively 
few  prickles"  (Piper,  loc.  tit.}.  But,  as  he  was  dealing  with  specimens 
from  Washington,  he  apparently  overlooked  the  literature  dealing  with 
X.  Wootoni,  which  had  been  known  only  from  New  Mexico; — hence 
the  reason  for  his  name  X.  oligacanihum. 

We  have  studied  several  authentic  specimens  from  New  Mexico  and 
from  Washington.  There  is  no  essential  difference  to  be  found  between 
the  two  sets  of  specimens.  Those  from  Washington  have  burs  more 
brownish  in  color  (rather  than  whitish  to  straw-colored)  and  the  prickles 
are  very  slightly  stouter.  But  both  have  the  beaks  of  the  burs  tending 


30      FIELD  MUSEUM  OF  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

to  be  strongly  cleft  or  2-valved  (sometimes  more  or  less  malformed),1 
and  in  various  other  characters  are  too  close  to  admit  of  any  taxonomic 
separation. 

The  specimens  collected  by  Deane  in  Massachusetts  have  the  nu- 
merous burs  identical  with  those  on  Piper's  plant  from  Washington, 
but  the  leaves  differ  noticeably  in  being  sharply  lobed  and  dentate. 
Our  knowledge  of  the  genus,  however,  convinces  us  that  the  foliage 
characters  are  entirely  too  unstable  to  warrant  satisfactory  segregation 
of  forms  when  unaccompanied  by  definite  characters  of  the  fruits. 
Hence  we  must  refer  the  Massachusetts  plants  to  this  species. 

10.  Xanthium  cenchroides,  sp.  nov. 

Caulis  longitudinaliter  plus  minusve  purpureo-maculatus,  supra 
subscabridus.  Folia  non  crassa,  dentata,  supra  scabrida,  infra  scabra  et 
minute  reticulata.  Fructus  (PI.  VII,  f.  10;  PL  VIII,  ff.  37-39)  ovati, 
superne  in  duo  rostra  producti;  exteriore  facie  glanduloso-hispida  et 
circum  25  aculeis  armata;  corpore  (rostris  non  adjectis)  1.5-1.7  cm. 
longo  et  6-7  mm.  lato;  rostris  arcuatis,  infra  hispidis,  supra  glabratis 
et  ad  apicem  hamosis,  circum  8  mm.  longis;  aculeis  rectis  aut  subrectis, 
infra  hispidis,  supra  glabris  et  ad  apicem  hamosis,  8-10  mm.  longis. 

DISTRIBUTION  :   Texas. 

SPECIMENS  EXAMINED:  TEXAS:  near  Ferris,  J.  Reverchon  2332 
(type  in  Hb.  Mo.  85563;  additional  material,  ibid.,  on  sheet  no.  85564). 

The  type  material  is  very  fragmentary,  the  leaves  nearly  all  having 
been  destroyed  by  worms.  The  fruiting  burs,  however,  are  present  in 
fair  quantity  and  are  very  distinct  from  those  of  any  other  Xanthium 
known  to  us.  In  their  small  number  of  prickles,  the  burs  resemble  those 
of  X.  Wootoni  Cockll.,  but  in  size  of  body,  length  of  prickles  etc.,  there 
are  very  pronounced  differences.  The  burs  suggest  very  strongly  the 
fruiting  involucres  of  Cenchrus  carolinianus  Walt.,  although  of  course 
much  larger. 

11.  XANTHIUM  INFLEXUM  Mack,  and  Bush,  Rept.  Missouri  Bot.  Gard. 

16:  106.     1905. 

Caulis  glabratus  aut  superne  setulis  albis  plus  minusve  scabridus, 
ramosus,  1—1.5  m.  altus.  Folia  cordata  aut  ovato-cordata,  tri-aut  sub- 
quinquelobata,  irregulariter  serrata  aut  dentata,  infirme  aut  valide 
scabrida,  petiolis  adjectis  0.8-2.5  dm.  longa,  petiolis  laminis  subaequan- 
tibus.  Fructuum  (PL  VII,  f.  n;  PL  IX,  ff.  1-4)  corpus  oblongo-ellip- 
ticum  aut  ovato-oblongum,  exteriore  facie  non  paucis  aculeis  armatum, 
aliter  glabrum  aut  sparsim  glandulosum,  1.3-1.7  (-2)  cm.  longum  et 
6-7.5  rnm.  crassum;  rostris  validis,  maturis  ad  medium  abrupte  flexis, 
valde  incurvatis,  ad  apicem  hamosis,  saepe  mutuo  contingentibus,  infra 

1  The  specimen  collected  by  Piper  has  several  burs  with  the  achenes  protruding 
at  the  top. 


APRIL,  1919.     XANTHIUM — MILLSPAUGH  AND  SHERFF.  31 

glanduloso-pubescentibus,  plerumque  5-7  mm.  longis  (auctores  "circ. 
10  mm.  longis"  dixerunt  inaccurate);  aculeis  tenuibus,  subconfertis, 
plerumque  arcuatis,  ad  apicem  hamosis,  infra  glanduloso-pubescentibus 
aut  demum  glabratis,  4.5-6.5  mm.  longis, saepequibusdamabnormalibus 
versus  rostra  longissimis  (8-10  mm.). 

DISTRIBUTION:   Southwestern  Illinois  to  Arkansas. 

SPECIMENS  EXAMINED:  MASSACHUSETTS:  Cambridge,  Botanical 
Garden,  Oct.,  1848,  from  seed  collected  by  Engelmann  (presumably 
collected  the  preceding  year  at  East  St.  Louis,  Illinois)  Asa  Gray  (two 
sheets  in  Hb.  Gray,  bearing  nos.  172,  1720  and  174).  ILLINOIS:  East 
St.  Louis,  river  bank,  Sept.,  1847,  George  Engelmann  (Hb.  Mo.  85551); 
MISSOURI:  Courtney,  in  bottoms,  B.  F.  Busk  869  (Hb.  Gray;  Hb.  Mo. 
85519;  an  atypic  form  apparently  hybridized  with  X.  pennsylvanicum 
Wallr.) ;  Courtney,  in  bottoms,  idem  1804  and  1805  (Hb.  Mo.  85409  and 
85531  respectively);  Courtney,  in  bottoms,  idem  1806  (Hb.  Mo.  85522; 
Hb.  Gray) ;  Courtney,  in  bottoms,  idem  1916  (Hb.  Mo.  85520  and  85521 ; 
Hb.  Gray; —  type  material).  ARKANSAS:  Fulton,  along  river,  B.  F. 
Bush  1026  (Hb.  Mo.  85554  and  85555;  Hb.  Gray; —  a  form  approaching 
X.  pennsylvanicum  Wallr.,  the  burs  having  long,  somewhat  delicate 
beaks,  which  are  not  decidedly  inflexed). 

Fortunately,  we  have  been  able  to  examine  fairly  numerous  speci- 
mens of  this  little  known  species.  The  burs  have  a  body  averaging  of 
larger  size  than  in  X.  chinense  Mill. ;  in  shape  and  appearance  the  body 
is  intermediate  between  that  in  X.  chinense  Mill,  and  that  in  X.  penn- 
sylvanicum Wallr.  The  prickles  are  long,  as  in  X.  speciosum  Kearney, 
but  more  slender,  much  smoother  and  somewhat  less  abundant. 

12.   X.  PENNSYLVANICUM  Wallr.1  Beitr.  Bot.  in:  236.     1844.;  Britton 
and  Brown  Illustr.  Fl.,  Edit.  II,  3:  346,  f.  4137.     1913. 

X.  pennsylvanicum  vars.  glandulosum  and  eglandulosum  Wallr. 
loc.  cit. 

X.  saccharatum  Wallr.  loc.  cit.  238; 

X.  affine  Greene,  Pittonia  4:  60.     1899. 

X.  californicum  Greene  and  X.  acutum  Greene,  loc.  cit.  62. 
Caulis  subtenuis  scabridus,  aut  infra  levis,  3-9  dm.  altus.  Folia 
deltoideo-ovata  aut  cordata,  dentata,  saepe  acute  3~5-lobata,  utrinque 
setulis  minutis  adpressis  scabra,  petiolis  adjectis  0.7-2  dm.  longa,  petiolis 
laminas  subaequantibus  aut  excedentibus.  Fructuum  (PI.  VII,  f.  12; 
PI.  IX,  ff.  5-10)  corpus  nunc  anguste  cylindricum,  nunc  oblongum, 
nunc  ovato-fusiforme,  nunc  etiam  ovoideum,  sed  plerumque  plus 
minusve  cylindricum,  glabrum  aut  glabratum  aut  pilis  glandulosis 
brevibus  vestitum,  1-2  cm.  longum  et  5-8  mm.  crassum,  aculeis  arma- 
tum;  rostris  tenuibus  aut  crassis,  infra  glanduloso-pubescentibus,  versus 

1  The  name  as  originally  given  by  Wallroth  was  spelled  X.  pensylvanicum. 
Fernald  (Rhodora  19:  70.  1917)  is  inclined  to  retain  the  old  spelling  in  such  cases 
and  gives  the  historical  reasons  for  pursuing  such  a  course. 


32      FIELD  MUSEUM  OP  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

apicem  glabris  et  saepius  incurvatis,  ad  apicem  hamosis,  4-6  mm. 
longis;  aculeis  subremotis  et  subvalidis  (aut  rarius  confertis  et  tenuibus), 
versus  basim  glandulosis  et  saepe  sparsim  pubescentibus,  aliter  glabris, 
ad  apicem  hamosis,  interdum  purpureo-tinctis,  3-7  mm.  longis. 

DISTRIBUTION  :  Massachusetts,  Ontario  and  Washington  to  Florida, 
Texas  and  California;  perhaps  also  in  Mexico;  frequent  in  the  Hawaiian 
Islands.  \ 

SPECIMENS  EXAMINED  (partial  list):1  MASSACHUSETTS:  Boston,  Sept. 
13,  1895,  Emile  F.  Williams  (Hb.  Gray).  RHODE  ISLAND:  Newport, 
waste  ground,  Fernald  and  Long  10658  (Hb.  Gray).  PENNSYLVANIA: 
without  locality,  invading  the  marshes  ("in  paludos"),  Sept.,  1824, 
Poeppig  (Hb.  Mo.  85594;  cotype  of  X.  pennsylvanicum  var.  eglandulosum 
Wallr.).  MARYLAND:  Plummer's  Island,  near  Cabin  John,  T.  H. 
Kearney  221  (Hb.  U.  S.  640384);  east  shore  of  Maxwell's  Point,  above 
tide,  George  H.  Shull  332  (Hb.  Gray) ;  shore  of  Chesapeake  Bay,  south  of 
Havre  de  Grace,  idem  390  (Hb.  Gray;  Hb.  Mo.  85436).  VIRGINIA: 
Alexandria  County,  near  Barcroft  Station,  Oct.  3,  1915,  E.  S.  Steele 
(Hb.  U.  S.  643281).  FLORIDA:  Hillsborough  County,  waste  ground, 
A.  Fredholm  6426  (Hb.  Gray).  ONTARIO:  near  Sarnia,  roadside  ditches, 
C.  K.  Dodge  49  (Hb.  Gray).  MICHIGAN:  Port  Huron,  dryish  ground  in 
streets,  C.  K.  Dodge  47  (Hb.  Gray).  ILLINOIS:  near  French  Village, 
Sept.  6,  1892,  H.  Eggert  (Hb.  Mo.  85438);  East  St.  Louis,  Sept.,  1847, 
Dr.  George  Engelmann  (Hb.  Mo.  85452);  Carthage,  F.  C.  Gates  9996 
(Hb.  Field  472736);  vicin.  of  Catlin,  bank  of  creek,  0.  E.  Lansing,  Jr., 
3532  (Hb.  Field  346590);  Urbana,  open  wet  soil,  Sept.  19,  1901,  M.  S. 
Sheldon  (Hb.  Gray) ;  Chicago,  along  walk,  Earl  E.  Sherjj  3080  (Hb.  Field 
480737  and  480738);  Hinsdale,  waste  ground,  Ernest  C.  Smith  529, 
(Hb.  Field  127018).  KENTUCKY:  locality  not  stated,  in  1842,  Dr.  C.  W. 
Short  (Hb.  Gray).  IOWA:  Decatur  County,  in  fields,  Aug.  29,  1897, 
Fitzpatrick  and  Fitzpatrick  (Hb.  Gray);  Ames,  without  date,  A.  S. 
Hitchcock  (Hb.  Mo.  85450).  MISSOURI:  Courtney,  in  bottoms,  B.  F. 
Bush  870  (Hb.  Mo.  85539);  Courtney,  in  bottoms,  idem  1789  (Hb. 
Gray);  Courtney,  in  bottoms,  idem  1790  (Hb.  Mo.  85538);  Courtney,  in 
bottoms,  idem  1792  (Hb.  Mo.  85530);  Courtney,  in  bottoms,  idem  1793 
(Hb.  Mo.  85542);  Courtney,  in  bottoms,  idem  1794  (Hb.  Mo.  85529); 
Courtney,  in  bottoms,  idem  1802  (Hb.  Gray;  Hb.  Mo.  85602) ;  Courtney, 
in  bottoms,  idem  1809  (Hb.  Mo.  85541);  Courtney,  in  bottoms,  idem 
1911  and  1914  (Hb.  Mo.  85540  and  85533  respectively;  probably  hybrid- 
ized with  X.  chinense  Miller) ;  Courtney,  in  bottoms,  idem  1915  (Hb.  Mo. 
85537);  St.  Louis,  Aug.  25,  1874,  H.  Eggert  (Hb.  Gray);  St.  Louis 
County,  West  Webster,  Dr.  J.  M.  Greenman  3799  (Hb.  Mo.  807756); 

1  A  large  number  of  specimens  omitted  here  from  lack  of  space. 


APRIL,  1919.     XANTHIUM — MILLSPAUGH  AND  SHERFF.  33 

Webb  City,  low  ground,  E.  J.  Palmer  767  (Hb.  Mo.  756626) ;  La  Russell, 
low  ground,  idem  1300  (Hb.  Mo.  85456;  fruit  with  bristly  prickles  and 
approaching  that  of  X.  italicum  Mor.).  ARKANSAS:  Fulton,  along  river, 
B.  F.  Bush  1027  and  1028  (Hb.  Mo.  85423  and  85543  respectively). 
NORTH  DAKOTA:  Leeds,  waste  places,  Aug.  21,  1902,  Dr.  J.  Lunell 
(Hb.Gray).  NEBRASKA:  Red  Cloud,  Rev.  J.M.  Bates  4745  (Hb.  Gray). 
KANSAS:  Manhattan,  Sept.  20, 1887,  W.  A.  Kellerman  (Hb.  Mo.  85449); 
Riley  County,  low  ground,  /.  B.  Norton  261  (Hb.  Mo.  85448).  OKLA- 
HOMA: Sapulpa,  B.  F.  Bush  299  (Hb.  Mo.  85544);  vicin.  Ottawa,  low 
waste  place,  G.  W.  Stevens  2568  (Hb.  Gray).  TEXAS :  Columbia,  in  sand, 
B.  F.  Bush  1344  (Hb.  Mo.  85467);  Dallas,  in  wastes,  /.  Reverchon  2589 
(Hb.  Mo.  85480,  85481  and  85546).  COLORADO:  Naturita,  moist  ditch 
bank,  Ernest  P.  Walker  545  (Hb.  Gray;  Hb.  U.  S.  544637).  NEVADA: 
Washoe  County,  Truckee  Pass,  Sept.  15,  1909,  A.  A.  Heller  (Hb.  Calif. 
196027;  a  form  with  burs  precisely  like  those  on  type  of  X.  acutum 
Greene  at  Hb.  Greene,  except  slightly  pubescent).  IDAHO:  New 
Plymouth,  waste  ground,  /.  Francis  Macbride  718  (Hb.  Gray,  having 
burs  almost  exactly  identical  with  those  on  type  of  X.  acutum  Greene, 
in  Hb.  Greene;  a  rather  immature  specimen  is  also  in  Hb.  Mo.  85515). 
UTAH:  Vermilion,  Marcus  E.  Jones  5842  (Hb.  Mo.  85490  and  85492); 
Peterson,  Peterson  Canyon,  Pammel  and  Blackwood  3888  (two  sheets  in 
Hb.  Gray);  road  between  Monticello  and  Bluffs,  Rydberg  and  Garrett 
9872  (Hb.  U.  S.  765345).  ARIZONA:  Tucson,Valley  of  Santa  Cruz  River, 
John  J.  Thornber  8  (Hb.  Mo.  85496;  Hb.  Calif.  129897).  WASHINGTON: 
Waitsburg,  bars  of  streams,  Robt.  M.  Homer  B  273  (Hb.  Gray;  this  is  not 
X.  varians  Greene  as  erroneously  stated  by  Piper,  Contrib.  U.  S.  Nat. 
Hb.  ii :  551.  1906) ;  West  Klickitat  County,  sandy  banks  of  Columbia 
River,  W.  N.  Suksdorf  1584  (Hb.  Field  89752  and  89753;  Hb.  Calif. 
130204;  Hb.  Gray;  Hb.  Greene  19830;  type  and  cotypes  of  X.  affine 
Greene).  OREGON:  Union  County,  Snake  River,  sand-bars,  W.  C. 
Cusick  1000  (Hb.  Gray);  near  Prineville,  /.  B.  Leiberg  842  (Hb.  Gray). 
CALIFORNIA:  Los  Angeles  County,  near  Soldiers'  Home,  Sept.,  1905, 
Dr.  J.  Q.  Adams  (Hb.  Calif.  74043) ;  San  Diego  County,  vicin.  Ramona, 
Stockton  Ranch,  Oct.,  1905,  Katharine  Brandegee  (Hb.  Calif.  168741; 
burs  identical  with  those  on  type  and  cotypes  of  X.  affine  Greene); 
vicin.  Ramona,  Stockton  Ranch,  Oct.,  1905,  eadem  (Hb.  Calif.  168816; 
a  form  with  burs  matching  those  on  type  of  X.  calif ornicum  Greene  in 
Hb.  Greene);  vicin.  Ramona,  Stockton  Ranch,  Oct.,  eadem  (Hb.  Calif. 
168813) ;  vicin.  Mendocino,  H.E. Brown  938  (Hb.  Mo.  85391 ;  this  is  not 
X.  echinatum  Murr.,  as  erroneously  stated  by  Thellung,  Verhandl.  Bot. 
Verein  Brandenb.  50°:  144.  1908);  roadside  near  Yreka,  George  D. 
Butler  527  (Hb.  Calif.  164145);  Escondido,  Harley  P.  Chandler  5399 


34      FIELD  MUSEUM  or  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

(Hb.  N.  Y.) ;  Temescal,  Oct.,  1889,  Edward L.  Greene  (Hb.  Greene  19822 ; 
Greene's  only  specimen  of  his  X.  californicum  and  by  us  regarded  as 
the  type;  matched  most  minutely  by  W.  L.  Jepson's  plant  from  Oak- 
land,—  see  below) ;  Amador  County,  Middle  Fork,  George  Hansen  700 
(Hb.  Mo.  85389) ;  Suisun  Marsh,  along  railroad  near  Suisun,  A.  A.  Heller 
7550  (Hb.  Gray;  Hb.  Mo.  85386;  Hb.  N.  Y.);  cultivated  land,  north  of 
Oroville,  idem  12647  (Hb.  Field  460600;  Hb.  Mo.  802978;  atypical  and 
approaching  X.  italicum  Mor.) ;  Rio  Vista,  bank  of  Sacramento  River, 
Sept.  16,  1891,  W.  L.  Jepson  (Hb.  Calif.  36799;  this  is  a  form  interme- 
diate between  the  types  of  X.  acutum  Greene  and  X.  californicum 
Greene,  in  Hb.  Greene);  Oakland,  Oct.  i,  1894,  idem  (Hb.  Mo.  85387; 
the  exact  form  described  by  Greene  as  X.  californicum  and  important 
as  coming  from  the  range  emphasized  by  him,  "Middle  California, 
especially  about  San  Francisco  Bay");  near  San  Francisco,  in  1866, 
Dr.  A.  Kellogg  (Hb.  Gray);  near  Stockton,  in  1888,  J.  A.  Sanford  (Hb. 
Greene  19819;  type  of  X.  acutum  Greene). 

Wallroth  divided  this  species  into  two  varieties,  o.  glandulosum  and 
ft.  eglandulosum,  according  to  the  presence  or  absence  of  minute  glands 
upon  the  fruits  and  lower  surfaces  of  the  leaves.  The  var.  glandulosum 
was  collected  by  Beyrich  at  Asheville  [North  Carolina]  in  1833,  while  the 
var.  eglandulosum  was  collected  by  Poeppig  in  Pennsylvania,  Sept.,  1824. 
We  have  not  seen  type  material  of  var.  glandulosum;  of  var.  eglandu- 
losum, however,  we  have  seen  the  cotype  specimen  in  the  Bernhardi 
Herbarium  (Hb.  Mo.  85594).  But  this  shows  clearly,  under  a  lens  with 
a  magnification  of  fourteen  diameters,  many  minute  glands, —  evidently 
missing  on  the  type  or  perhaps  overlooked  by  Wallroth.  Thus  Wall- 
roth's  separation  of  the  species  into  two  varieties  is  seen  to  be  without 
real  basis  in  fact. 

Among  botanists  there  has  been  almost  endless  confusion  between 
X.  pennsylvanicum  and  the  species  treated  below  as  true  X.  italicum 
Mor.  Our  own  experience  in  the  herbarium  indicates  these  to  be,  with- 
out question,  distinct.  In  the  field,  our  numerous  observations  during 
the  season  of  1918  show  that,  where  the  two  grow  side  by  side,  X. 
italicum  commonly  displays  a  more  compact  mass  of  burs  near  the  apex 
of  the  stem  and  branches  than  does  X.  pennsylvanicum.  This  com- 
pactness, added  to  the  greater  pubescence  of  the  burs,  often  imparts  to 
X.  italicum  an  appearance  very  unique. 

Of  X.  saccharatum  Wallr.,  there  is  the  cotype  in  Gray  Herbarium. 
This  is  plainly  X.  pennsylvanicum.  We  find  a  badly  scrawled  name 
given  for  the  locality  to  say  "Bexar."  Clearly  the  plant  (Berlandier 
1865}  was  collected  at  Bexar,  Texas,  and  not  in  Mexico  as  some  writers 
have  persisted  in  stating  (although,  to  be  sure,  Texas  had  been  a  part 


APRIL,  1919.      XANTHIUM — MILLSPAUGH  AND  SHERFF.  35 

of  Mexico  until  shortly  before  Wallroth's  publication  of  the  name  X. 
saccharatum) . l 

Of  X.  affine  Greene,  X.  californicum  Greene2  and  X.  acutum  Greene, 
we  have  seen  the  types  (all  in  Hb.  Greene);  of  X.  affine  we  have  seen 
also  various  cotypes.  So  different  do  these  forms  appear  at  first  that  one 
might  well  mistake  them  as  typifying  three  distinct  species.  However, 
the  large  number  of  herbarium  specimens  that  we  have  examined  from 
the  Pacific  Coast  show  that  specific  segregation  is  entirely  impossible. 
So  polymorphous  does  X.  pennsylvanicum  become  in  its  western  range 
that,  in  California  alone,  as  many  as  six  or  seven  forms  may  be  found. 
In  the  eastern  part  of  the  United  States,  X.  pennsylvanicum  displays 
much  less  variation,  both  in  fruits  and  in  general  habit. 

13.   Xanthium  calvum  sp.  nov.  PI.  XII. 

Caulis  erectus,  rubescens,  saepe  maculis  purpureis  parvis  longitu- 
dinalibus  punctatus,  subscabridus  aut  infra  etiam  glaber,  circ.  4-9  dm. 
altus.  Folia  ovato-cordata  aut  ovato-triangulata,  ad  basim  vel  orbicu- 
lata  vel  truncata  vel  cordata,  plerumque  atro-viridiora,  crenato-dentata, 
saepe  dentato-lobata,  setulis  minutis  adpressis  scabrida,  petiolis  adjectis 
0.6-2  dm.  longis,  petiolis  laminis  subaequantibus.  Fructus  (PI.  VII, 
f.  13;  PI.  IX,  ff.  11-12)  pauci  aut  numerosi,  corpore  crasso  ovato- 
fusiformi  fusco,  utrinque  subacuto,  exteriore  facie  breviter  et  minime 
pubescenti,  glanduloso,  aculeis  subremotis  armato,  1.5-1.8  cm.  longo, 
circum  8  mm.  crasso;  rostris  infra  crassis  et  validis,  ad  basim  glanduloso- 
pubescentibus,  ad  medium  plerumque  inflexis,  ad  apicem  plus  minusve 
hamosis,  3-5  mm.  longis;  aculeis  rectis,  ad  basim  glandulosis  aut  ranter 
pubescentibus,  aliter  glabris,  ad  apicem  hamosis,  4-6  mm.  longis; 
rostris  et  aculeis  plerumque  purpureo-tinctis,  praesertim  versus  apicem. 

DISTRIBUTION:   California. 

SPECIMENS  EXAMINED:  CALIFORNIA:  vicin.  of  Palo  Alto,  foothills, 
C.  F.  Baker  1760  (Hb.  Calif.  131236,  type;  Hb.  Field  226601;  Hb.  Gray; 
Hb.  Mo.  85385;  Hb.  N.  Y.);  Neponset,  Salinas  River,  L.  R.  Abrams 
4023  (Hb.  Calif.  149139);  West  Berkeley,  Harriet  A.  Walker  478  (Hb. 
Calif.  130051). 

1  It  may  be  remarked  that  the  type  of  X.  crassifolium  Millsp.  and  Sherff  (Field 
Mus.  Bot.  4:  5. 1918)  was  collected  at  San  Antonio,  not  far  from  Bexar,  in  Bexar 
County,  Texas.  The  two  plants  show  a  close  resemblance,  but  the  Berlandier  plant 
is  much  thinner-leaved  and  less  scabrous.  We  are  disposed  to  consider  X.  crassifolium 
as  probably  a  variety  or  race  of  X.  pennsylvanicum,  —  a  conclusion  that  we  have 
reached  also  in  the  case  of  X.  acutilobum  Millsp.  &  Sherff  (he.  cit.,  p.  6).  Since  de- 
scribing X.  crassifolium  (Field  Mus.  Bot.  4:4.  1918)  we  have  found  several  somewhat 
intermediate  herbarium  specimens.  One  of  these,  C.  L.  Shear  220,  vicin.  of  Osborne 
City,  Kansas,  Aug.  27,  1894  (Hb.  Gray),  has  the  coarse,  highly  scabrous  stem  and 
leaves  of  X.  crasstfolium,  but  the  leaves  are  large,  as  in  X.  pennsylvanicum. 

JAt  various  times  in  later  years,  Dr.  Greene  erroneously  determined  certain 
specimens  of  Xanthium  as  representing  his  X.  californicum.  These  belonged  to 
X.  pennsylvanicum,  X.  calvum,  etc.  Greene's  own  type  specimen  of  X.  califor- 
nicum was,  as  stated  above,  the  same  form  as  that  collected  by  W.  L.  Jepson,  Oak- 
land, California,  Oct.  i,  1894  (Hb.  Mo.  85387),  a  form  of  X.  pennsylvanicum. 


36      FIELD  MUSEUM  or  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

A  species  with  very  unique  aspect  of  foliage  as  well  as  of  fruit.  Speci- 
mens of  the  type  collection  had  been  determined  by  E.  L.  Greene  as 
X.  calijornicum  Greene  (cf.  p.  35,  footnote  2).  But  a  study  of  Greene's 
type  of  X.  californicum  shows  no  approach  in  fruit  characters  to  the 
type  of  X.  calvum.  We  have  seen  several  sheets  of  X.  pennsylvanicum 
having  fruits  typical  of  that  species  but  with  foliage  offering  a  perplexing 
resemblance  to  that  of  X.  calvum  (e.g.,  C.  F.  Baker  1512,  along  borders 
of  marshes,  Palo  Alto,  California,  Hb.  Gray;  Harley  P.  Chandler  5399, 
Escondido,  California,  Hb.  Calif.  64835).  Future  investigation  upon  the 
status  of  such  forms,  which  are  possibly  hybrids,  would  seem  highly 
desirable. 

The  specific  designation  calvum  is  given  in  allusion  to  the  bald  or 
smoothish  appearance  of  the  body  and  prickles  of  the  mature  fruit. 

14.   XANTHIUM  PALUSTRE  Greene,  Pittonia  4:   63.    1899. 

Caulis  glaber  aut  paulo  scabridus,  interdum  rubescens,  saepe  lineis 
purpureis  longitudinalibus  maculatus,  verisimiliter  0.5-1  m.  altus. 
Folia  ovato-cordata  aut  deltoidea,  dentata,  plus  minusve  lobata,  utrin- 
que  setulis  minutis  adpressis  scabra,  petiolis  adjectis  0.8-3  dm.  longa, 
petiolis  laminas  subaequantibus  aut  excedentibus.  Fructuum  (PI.  VII, 
f.  14;  PI.  IX,  ff.  13-15)  corpus  viridi-fuscum,  demum  crasso-oblongum 
et  nitens,  glandulosum  sed  parce  pubescens,  circ.  1.8  cm.  longum  et 
8—9  mm.  crassum,  aculeis  brevibus  armatum;  rostris  brevibus,  crassis, 
pubescentibus,  supra  incurvatis,  ad  apicem  saepe  subhamosis,  3-5  mm. 
longis;  aculeis  numerosis  sed  vix  confertis,  versus  basim  crassum  glandu- 
losis  et  saepe  sparsim  pubescentibus,  supra  tenuibus  et  glabris,  ad 
apicem  hamosis,  2-2.5  (ranter  3-3.5  aut  etiam  -4)  mm.  longis. 

DISTRIBUTION  :   California. 

SPECIMENS  EXAMINED:  CALIFORNIA:  Suisun  Marsh, in  1893, Edw.L. 
Greene  (Hb.  Greene  19833  and  19834;  type  sheets);  Lathrop,  Harriet  A. 
Walker  926  (Hb.  Calif.  201224);  Suisun,  eadem  973  (Hb.  Calif.  128022). 

In  Greene's  Herbarium  are  two  specimens  to  represent  this  rare  and 
little  known  species,  both  of  them  collected  by  Greene  himself  at  Suisun 
Marsh,  and  which  may  properly  be  taken  as  the  types  of  the  species. 
These  have  fruits  just  as  described  by  Greene,  except  that  they  are  more 
nearly  oblong  than  he  implied  and  had  best  not  be  described  as  "slightly 
obovate-oblong."  Furthermore,  they  tend  toward  a  greenish-brown  in 
color,  with  some  of  the  prickles  becoming  reddish. 

The  first  specimen  by  Miss  Walker  (listed  above)  is,  in  our  opinion, 
clearly  X.  palustre,  but  it  shows  an  approach  toward  X.  pennsylvanicum 
Wallr.  in  having  prickles  3-3.5  (a  few  even  4)  mm.  long.  Miss  Walker's 
second  specimen  (no.  973),  however,  comes  from  the  type  locality  and 
matches  the  two  type  specimens  identically,  both  as  to  foliage  and  as  to 
fruits. 


APRIL,  1919.     XANTHIUM — MILLSPAUGH  AND  SHERFF.  37 

15.   Xanthium  australe  sp.  nov.  PL  XIII. 

Caulis  scabridus,  plus  minusve  maculis  purpureis  parvis  linearibus 
punctatus,  verisimiliter  0.5-1  m.  altus.  Folia  petiolata,  trinervia, 
deltoideo-cordata,  saepe  obscure  lobata,  dentata,  utrinque  setulis  minu- 
tis  adpressis  vestita,  petiolis  adjectis  0.8-2  dm.  longa,  petiolis  laminis 
subaequantibus.  Fructuum  (PI.  VII,  f.  15;  PL  IX,  ff.  16-18)  corpus 
ovoideo-subglobosum,  subsparsim  glanduloso-pubescens  aut  glabratum, 
0.9-1.1  cm.  longum  et  6-7  mm.  crassum  (aut  etiam  1.3-1.5  cm.  longum 
et  8-9  mm.  crassum,  in  specimine  chilensi),  aculeis  confertis  armatum; 
rostris  attenuatis,  rectis  aut  paulo  inflexis,  ad  apicem  subrectis  aut 
uncinatis,  infra  pubescentibus,  6-9  mm.  longis;  aculeis  tenuibus,  rectis 
aut  paulo  arcuatis,  infra  nee  dense  nee  longe  pubescentibus  (in  specimine 
chilensi  quibusdam  aculeis  glandulosis  et  non  pubescentibus),  supra 
glabris,  ad  apicem  uncinatis,  4-5  mm.  longis. 

DISTRIBUTION:   Mexico,  Paraguay  and  Chile. 

SPECIMENS  EXAMINED:  TAMAULIPAS:  vicin.  of  La  Barra,  8  km.  east 
of  Tampico,  at  sea-level,  Dr.  Edward  Palmer  275  (Hb.  U.  S.  463216, 
type).  PARAGUAY:  Asuncion,  Thomas  M  or  ong  807  (Hb.  N.  Y.).  CHILE: 
Valparaiso,  Dr.  Mertens  (ex  Hb.  Acad.  Petrop.,  in  Hb.  Gray). 

The  long  fruiting  beaks  of  this  species  suggested  to  us  at  first  an 
affinity  with  the  long-beaked  West  Indian  form  of  X.  chinense  Mill. 
(X.  longirostre  Wallr.).  A  consideration,  however,  of  the  other  fruit 
characters,  as  well  as  of  foliage,  shows  no  further  relationships  of  a 
specific  nature. 

There  is  a  slight  possibility  that  this  is  the  species  which  Vellozo  had 
in  mind  when  figuring  his  Xanthium  brasilicum.  But  a  careful  inspec- 
tion of  Vellozo's  plate  (Fl.  Flum.  10:  tab.  23.  1827)  shows  it  to  be  all 
too  crude  and  lacking  in  definite  detail  to  permit  of  satisfactory  inter- 
pretation.1 Indeed,  if  the  plate  be  at  all  accurate,  it  clearly  represents 
some  other  species,  for  the  characters  of  the  bur  as  there  shown  are  not 
those  of  X.  australe.2 

1  It  is  surprising  to  find  that  Baker  (Martius  Fl.  Bras.  6ra:    147.    1884),  notwith- 
standing the  crudity  of  this  plate,  actually  made  it  the  basis  for  a  new  combination 
in  nomenclature,  X.  strumarium  L.  var.  brasilicum  (Velloz.)  Baker. 

2  We  have  seen  no  authentic  material  of  the  inadequately  described  X.  homo- 
thalamum  of  Sprengel  (Neue  Entdeck.  i:    259.    1820)  from  Brazil.    We  note  that 
the  name  X.  homothalamum  was  entirely  omitted  by  Baker  from  his  treatment  of 
Brazilian  Xanthia  (Martius  Fl.  Bras.  6m:    147.    1884).   Sprengel  himself  appears  to 
have  seen  only  scanty  material  of  the  plant  ("Licet  haut  perfecta  huius  plantae 
exemplaria  investigare  potuerim,"  loc.  cit.,  p.  260).    He  described  the  fruits  briefly: 
"In  ambitu  sex  aut  octo  drupae  oblongae  sulcatae,  aculeis  flavis  uncinatis  armatae. 
Singulae  continent  semen  testa  fusco-nigra  obductum,  in  quo,  sine  albumine,  embryo 
rectus  oblongis  cotyledonibus  mediocriter  carnosis,  sedet."    We  find  nothing  in  his 
description  which  might  justify  the  reference  of  our  X.  australe  to  X.  homothalamum. 


38      FIELD  MUSEUM  OF  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

1 6.   XANTHIUM  ECHINATUM  Murr.,  Comm.  Goetting.  6:32  and  tab.  4. 

1783-1784. 

X.  maculatum  Raf.,  Amer.  Journ.  Sc.  i:  151.  iSig.1 
Caulis  scaber  aut  scabrido-hispidus,  purpureo-maculatus,  3-6  dm. 
altus.  Folia  setulis  adpressis  scabra,  plerumque  cordata  et  obtuse 
lobata,  obtuse  et  remote  dentata  aut  serrata,  petiolis  adjectis  0.6-2.3 
dm.  longa,  petiolis  laminas  subaequantibus  aut  excedentibus.  Fructuum 
(PI.  VII,  f.  16;  PI.  IX,  ff.  19-21)  corpus  crasso-ovale  aut  rare  sub- 
globosum,  glanduloso-hispidum  et  aculeis  subremotis  armatum,  demum 
1.6-2  cm.  longum  et  0.8-1  cm.  crassum;  rostris  validis,  incurvatis,  ad 
apicem  saepius  hamosis,  infra  hispidis,  3-5  mm.  longis;  aculeis  tenuibus, 
rectis  aut  arcuatis,  ad  basim  (aut  usque  ad  medium)  hispidis,  supra 
calvis,  ad  apicem  saepius  hamosis,  rostris  subaequantibus. 

DISTRIBUTION:  Quebec  to  New  Jersey,  also  (apparently  adventive) 
in  Virginia,  Ontario,  North  Dakota  and  Missouri. 

SPECIMENS  EXAMINED:  QUEBEC:  Longueuil,  shores  of  St.  Lawrence 
River,  Brother  Victorin  1056  (Hb.  Gray).  ONTARIO:  Ottawa,  McKay 
Lake,  Aug.  3,  1911,  John  Macoun  (Can.  Geol.  Surv.  no.  87545  in  Hb. 
Mo.,  no.  719897).  MAINE:  Prouts  Neck,  Sept.,  1898,  Miss  M.  E.  Blatch- 
ford  (Hb.  Gray).  NEW  HAMPSHIRE:  Newcastle,  Little  Harbor,  Sept.  19, 
1901,  Entile  F.  Williams  (Hb.  Gray).  MASSACHUSETTS:  Boston,  Savin 
Hill,  Aug.  28, 1853,  William  Boott  (Hb.  Gray);  Cape  Cod,  Hyannis  Port, 
/.  M.  Greenman  361  (Hb.  Mo.  722293);  Pemberton,  sandy  beach,  Aug. 
27,  1897,  B.  L.  Robinson  (Hb.  Gray);  Nonquitt,  Aug.  27,  1888,  E.  L. 
Sturtevant  (Hb.  Mo.  85501);  Nonquitt,  along  sea-shore,  Sept.  25,  1888, 
idem  (Hb.  Mo.  85500);  Dartmouth,  roadside,  Sept.  27,  1889,  idem  (Hb. 
Mo.  85502);  Revere,  seashore  sands,  Aug.  22,  1896,  Emile  F.  Williams 
(Hb.  Gray);  Craigville,  sandy  roadside,  Sept.  5,  1898,  idem  (Hb.  Gray); 
Scituate,  seashore,  Oct.  29,  1899,  idem  (Hb.  Gray);  North  Scituate, 
Sept.  6,  1897,  idem  (Hb.  Gray).  RHODE  ISLAND:  Block  Island,  sandy 
sea-beach,  southwest  of  Chagum  Pond,  Fernald,  Hunnewell  2nd  and 
Long  10659  (Hb.  Gray);  without  locality,  in  1848,  Flint  (Hb.  Gray). 
NEW  YORK:  Long  Island,  Rockaway  Beach,  Sept.,  1892,  Dr.  Smith  Ely 
Jellife  (Hb.  Field  396974).  NEW  JERSEY:  Ocean  County,  Tom's  River, 
sea-beaches,  Kenneth  K.  Mackenzie  1046  (Hb.  Mo.  85503).  VIRGINIA: 
Cape  Charles  City,  Canby  and  Rose  845  (Hb.  U.  S.  297952; —  an  anomal- 
ous form  with  burs  glabrate  but  glandular  upon  the  body,  offering  a 
strong  superficial  resemblance  to  X.  palustre  Greene).  MISSOURI: 
Allenton,  Sept.  20,  1890,  George  W.  Letterman  (Hb.  Mo.  775049; — a 
form  with  burs  approaching  those  of  X.  italicum  Mor.).  NORTH  DAK- 

1  Torrey  and  Gray  (Fl.  N.  Amer.  2:  295.  1843)  described  a  variety  of  X. 
echinatum  Murr.  ("j8.  prickles  of  the  oval-oblong  fructiferous  involucre  stouter  and 
less  crowded;  leaves  incisely  lobed")  from  the  "banks  of  Spirit  Lake,  head-waters  of 
the  Little  Sioux  River  of  the  Missouri,  Mr.  Nicolletl"  We  have  seen  no  authentic 
material  of  this  variety. 


APRIL,  1919.     XANTHIUM — MILLSPAUGH  AND  SHERPF.  39 

OTA:  Leeds,  fields,  Aug.  i6-Sept.  6,  1899,  Dr.  J.  Lunell  (Hb.  Gray); 
Leeds,  along  running  water,  Aug.  28,  1902,  idem  82  (Hb.  Gray). 

This  species  was  badly  confused  by  Wallroth  (Beitr.  Bot.  in:  239. 
1844)  with  the  true  X.  orientale  L.  Indeed,  many  other  botanists  have 
fallen  into  similar  errors,  so  that  in  literature  we  find  X.  echinatum 
erroneously  equated  with  a  number  of  entirely  distinct  species.  Thus, 
for  example,  Thellung  (Verhandl.  Bot.  Verein  Brandenb.  50":  142-144. 
1908)  actually  gives  as  synonyms,  X.  italicum  Mor.,  X.  pennsylvanicum 
Wallr.,  X.  riparium  Lasch,  X.  campestre  Greene1  and  X.  chinense  Mill. 

Murray's  original  description  not  only  was  very  complete  but  was 
accompanied  by  a  good  plate.2  This  plate  shows  the  fruiting  involucres 
to  have  an  ovoid  body,  with  short,  rather  remote  prickles  and  very  wide 
achenes  (ff.  i,  7  and  8).  Thellung  (loc.  tit.)  attempts  to  differentiate 
between  Murray's  description  and  plate,  retaining  the  former  and 

excluding  the  latter.  But  Murray's  description  (" 

Capsula  ovalis,  olivae  magnitudinis,  hirsuta,  antice  hamosa,  hamis 
inflexis  hispidis,  vestita  aculeis  uncinatis,  divergentibus,  consertis,  sur- 
sum  et  apice  nudis,  basi  deorsum  echinatis  per  setas  rigidas  albidas, 
rectiores;  bilocularis ")  harmonizes  perfectly,  in  our  opin- 
ion, with  the  plate.  Moreover,  Murray  himself  stated  that  his  plant, 
raised  in  1783,  came  from  fruits  sent  him  by  Von  Wangenheim,  from 
New  York.  And  it  is  precisely  in  the  Atlantic  coastal  region  beginning 
with  New  York  and  extending  north  and  south  that  almost  all  the 
plants  matching  Murray's  plate  and  description  are  found.  Still  fur- 
ther, Murray's  reference  to  an  olive  in  describing  the  fruits  ("Capsula 
ovalis,  olivae  magnitudinis")  is  very  significant.  The  plants  cited  in 
our  foregoing  list  as  representing  true  X.  echinatum,  display,  more  than 
any  other  native  species  of  Xanthium  from  Eastern  North  America, 
an  open,  plump,  ovoid  appearance  to  the  body  of  the  bur  in  such  a  way 
as  to  suggest  an  olive. 

Numerous  authors,  like  Thellung,  have  confused  X.  echinatum  with 
the  European  X.  riparium  Lasch.  All  the  European  specimens  of 
X.  riparium  examined  by  us  (about  fifteen  sheets)  have  shown  burs 
uniformly  smaller,  much  narrower  and  with  much  smaller  achenes. 
It  appears  to  us  probable  that  no  European  botanist,  after  examining 
several  American  specimens  of  X.  echinatum,  would  hesitate  to  regard 
X.  riparium  as  distinct. 

The  plant  described  by  Rafinesque  (loc.  tit.)  as  X.  maculatum,  came 

1  Thellung  had  seen,  for  X.  campestre.only  an  incorrectly  determined  specimen, 
H.  E.  Brown  938. 

a  Cf.  Torr.  and  Gray  (Fl.  N.  Amer.  2:  295.  1843),  who  referred  to  this  plate  as 
"a  good  figure."  But  Thellung  (loc.  «'/.),  who  clearly  had  a  very  incorrect  con- 
ception of  Murray's  species,  called  the  plate  very  bad  ("pessima"). 


40      FIELD  MUSEUM  or  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

likewise  from  "the  neighbourhood  of  New  York" ("on  Long 

Island,  near  the  sea-shore  and  marshes").  Rafinesque  distinguished  his 
plant  from  X.  echinatum,  stating  that  X.  echinatum  had  "oval  fruits, 
with  aggregated,  echinate,  and  hooked  thorns."  Without  doubt,  he  had 
in  mind  not  the  true  X.  echinatum  Murr.  but  rather  the  plant  later 
described  by  Moretti  as  X.  italicum.  The  fruits  of  his  X.  maculatum  he 

described  as  "generally  solitary half  an  inch  long,  nearly 

cylindrical  obtuse,  with  the  two  beaks  scarcely  perceptible  and  bent  in, 
covered  with  short,  thick  and  rough  thorns,  rather  soft,  and  not  uncinate." 
From  these  characters  (especially  the  ones  which  we  have  emphasized 
with  italics)  as  well  as  from  the  habitat  given  ("near  the  sea-shore 
and  marshes"),  we  feel  certain  that  by  X.  maculatum  Rafinesque  meant 
the  plant  which  was  really  the  true  X.  echinatum  Murr. 

17.  XANTHIUM  ITALICUM  Mor.,  Brugnatelli  Giorn.  fis.,  chim.  Dec.  II., 
5:  326.  1822;  Reichenbach  Iconographia  Botanica  4:  22,  tab. 
323.  1826. 

X.  varians  Greene,  Pittonia  4:  59.     1899. 

X.  glanduliferum  Greene,  loc.  tit.,  61. 

X.  commune  Britton,  Manual  912.     1901. 

£.  Macounii  Britton,  he.  tit.     913.* 

Caulis  ramosus,  scaber,  lineis  atro-purpureis  saepe  maculatus,  3-10 
(-18  fide  Moretti)  dm.  altus.  Folia  cordata  aut  late  ovata,  lobata, 
dentata,  utrinque  setulis  adpressis  scabra,  petiolis  adjectis  0.8-3  dm. 
longa,  petiolis  laminis  subaequantibus  aut  excedentibus.  Fructuum 
(PI.  VII,  f.  17;  PL  IX,  ff.  25-30)  corpus  nunc  cylindricum,  nunc  oblong- 
um,  nunc  ovoideum,  sed  saepius  late  oblongum,  facie  exteriore  glandu- 
loso-pubescens  et  aculeis  armatum,  1.3-1.8  cm.  longum,  6-8  mm. 
crassum;  rostris  plerumque  incurvatis  et  ad  apicem  hamosis,  hispidis, 
5-7  mm.  longis;  aculeis  saepius  numerosis  et  tenuibus  (rariter  vel  sub- 
remotis  vel  subcrassis),  infra  hispidis  usque  ad  medium,  supra  glabris, 
ad  apicem  hamosis,  3-7  mm.  longis. 

DISTRIBUTION  :  Quebec,  Connecticut  and  West  Virginia  to  Saskatche- 
wan, Washington,  California  and  Oaxaca;  southern  Europe,  Hawaiian 
Islands,  and  probably  elsewhere. 

1  We  are  not  able  to  determine  satisfactorily  the  identity  of  X.  Cavanillesii 
Schouw  (Ind.  Sem.  Hort.  Haun.:  14.  1849;  Ann.  Sc.  Nat.  s6r.  Ill,  12:  357.  1849). 
Cavanilles'  type  plate  (Cav.  Icon.  3:  tab.  221.  1794)  cited  by  Schouw,  shows  the 
fruits  glabrous,  except,  of  course,  as  to  beaks  and  prickles.  If  this  plate  be  assumed 
to  be  accurate,  then  the  plant  figured  was  undoubtedly  X.  chinense  Mill.  If,  as  seems 
just  as  likely  however,  Cavanilles'  plate  was  rather  generalized  and  lacking  in 
detail,  as  are  many  of  his  other  plates,  then  his  plant  specimen  probably  possessed 
hispid-aculeate  fruit  and  belonged  to  X.  italicum.  Cavanilles'  description  of  the  fruit 
(loc.  cit.,  p.  n)  is  devoid  of  details  as  to  pubescence:  "Fructus  ovato-oblongus, 
pollicaris,  estque  drupa  sicca,  undique  aculeis  uncinatis  tecta,  apice  bifida,  cuius 
mix  bilocularis."  Schouw's  own  description  of  the  fruit  ("Involucre  fructigero 
ovali,  inter  aculeos  et  ad  basin  rostrorum  hispidissimo;  aculeis  tenuiter  subulatis, 
strictis,  infer ioribus  retrorsum  porrectis;  rostris  tenuibus,  strictis,  apice  un- 
cinatis"), based,  however,  upon  a  specimen  from  Buenos  Ayres,  by  Didrichsen, 
might  well  pass  for  that  of  X.  italicum. 


APRIL,  1919.     XANTHIUM — MILLSPAUGH  AND  SHERFF.  41 

SPECIMENS  EXAMINED  (partial  list) :  QUEBEC:  Leamy's  Lake,  Sept. 
n,  1891,  /.  Macoun  (Hb.  N.  Y.).  NEW  HAMPSHIRE:  Charlestown,  dry 
sandy  open  roadsides,  Sept.  16,  1899,  B.  L.  Robinson  (Hb.  Gray). 
VERMONT:  Springfield,  open  dry  sandy  roadside,  Sept.  16,  1899,  B.  L. 
Robinson  (Hb.  Gray).  NEW  YORK:  Westport,  shores  of  Lake  Cham- 
plain,  Sept.  15,  1900,  Dr.  and  Mrs.  N.  L.  Britton  (Hb.  N.  Y.;  type  of 
X.  commune  Britton) ;  Sandy  Hill,  along  Champlain  Canal,  Stewart  H. 
Burnham  27  (Hb.  Gray);  Ogdensburg,  Orra  Parker  Phelps  1212,1213 
and  1214  (Hb.  Gray);  Hogansburg,  banks  of  St.  Regis  River,  eadem 
1216  (Hb.  Gray).  CONNECTICUT:  Plainfield,  waste  ground,  Sept.  6, 
1908,  Bissell  and  Weatherby  (Hb.  Gray);  Bridgeport,  dry  roadsides, 
E.  H.  Eames  I  (Hb.  Gray).  PENNSYLVANIA:  Lancaster,  Oct.  7,  1901, 
A,  A.  Heller  (Hb.  Field  430065;  Hb.  Gray; — a  form  with  burs  sug- 
gesting X.  pennsylvanicum).  Lancaster,  Dillerville  Swamp,  Sept.  24, 
1889,  John  K.  Small  (Hb.  Field  168555).  MARYLAND:  shore  of  Chesa- 
peake Bay,  south  of  Havre  de  Grace,  George  H.  Shull  391  (Hb.  Gray; 
Hb.  Mo.  85504).  DISTRICT  OF  COLUMBIA:  shore  of  Potomac  River, 
Sept.  3,  1876,  Lester  F.  Ward  (Hb.  U.  S.  130953).  VIRGINIA:  along 
Potomac  River,  opposite  Washington,  D.  C.,  Oct.  2,  1904,  E.  S.  Steele 
(Hb.  U.  S.  504661).  WEST  VIRGINIA:  Hendricks,  dry  places  along  Black- 
water  River,  /.  M.  Greenman  537  (Hb.  Field  345708;  Hb.  Gray;  form 
matching  type  of  X.  commune  Britt.  very  closely).  INDIANA:  Bluffton, 
Sept.  9,  1897,  Charles  C.  Deam  (Hb.  Field  123387);  vicin.  Bluffton,  idem 
548,  (Hb.  Mo.  85437).  Kentucky:  locality  not  stated,  Dr.  C.  W.  Short, 
in  1842  (Hb.  Gray).  ILLINOIS:  East  St.  Louis,  Stockyards,  Sept.  10, 
1886,  H.  Eggert  (Hb.  Mo.  759571);  sandy  shore  of  Lake  Michigan, 
Frank  C.  Gates  50  (Hb.  Field  458182);  Champaign  County,  Urbana 
Township,  roadside,  idem  2112  (Hb.  Field  246297;  an  atypic  form  with 
prickles  more  remote) ;  Winthrop  Harbor,  idem  3228  (Hb.  Field  345082 
and  459041);  Urbana,  Sept.  19,  1901,  A.  Gilkerson  (Hb.  Gray;  atypic 
form  with  subremote  prickles,  approaching  X.  pennsylvanicum  Wallr.) ; 
Metropolis,  banks  of  Ohio  River,  Aug.  14,  1902,  H.  A.  Gleason  (Hb. 
Gray);  Champaign,  field,  A.  S.  Pease  13009  (Hb.  Gray);  Chicago,  along 
sidewalk,  Earl  E.  Sherjj  3079  (Hb.  Field  480735  and  480736);  Chicago, 
along  sidewalk,  idem  3081  (Hb.  Field  480739).  IOWA:  Ames,  M. 
Clapper  10  (Hb.  Gray;  Hb.  Mo.  85441).  MISSOURI:  Courtney,  in  bot- 
toms, B.  F.  Bush  1813  (Hb.  Mo.  85601);  Courtney,  in  bottoms,  idem 
ipio  (Hb.  Mo.  85458);  Sheffield,  idem  2216  (Hb.  Mo.  85459);  Webb 
City,  in  cultivated  fields,  E.  J.  Palmer  1039  (Hb.  Mo.  756627);  Webb 
City,  waste  places,  idem  1303  (Hb.  Mo.  85509  and  756631);  Noel, 
Butler  Creek,  gravel  bars,  idem  4219  (Hb.  Mo.  716540).  SOUTH  DAKOTA: 
Watertown,  John  J.  Thornber,  Aug.,  1892,  (Hb.  Gray).  NEBRASKA: 


42     FIELD  MUSEUM  OP  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

Arcadia,  Rev.  J.  M.  Bates  5400  (Hb.  Gray).  TEXAS:  Dallas,  common  on 
prairie,  B.  F.  Bush  1154  (Hb.  Mo.  85477) ;  San  Antonio,  Mr.  and  Mrs.  J. 
Clemens  953  (Hb.  Mo.  808717);  Graham,  J.  Reverchon  3279  (Hb.  Mo. 
85473).  SASKATCHEWAN:  "South  Saskatchewan,"  J.  Macounqi  (Hb. 
Gray;  a  small-fruited  form).  MONTANA:  Great  Falls,  Sept.  16,  1885, 
F.  W.  Anderson  (Hb.  Chi.  360828).  COLORADO:  Denver,  common  in 
damp  alkaline  soil,  Alice  Eastwood  154  (Hb.  Gray;  Hb.  Calif.  148085); 
vicin.  La  Junta,  Rose  and  Fitch  17507  (Hb.  U.  S.  760583).  NEW 
MEXICO:  Nara  Visa,  Oct.  7,  1910,  Geo.  L.  Fisher  (Hb.  Mo.  818395); 
Mesilla  Valley,  Oct.  13,  1906,  Paul  C.  Standley  (Hb.  Mo.  85488); 
Mesilla  Valley  (Donna  Ana  County),  College  farm,  Oct.  15,  1901,  E.  O. 
Wooton  (Hb.  Mo.  85487);  Mesilla  Valley,  Wooton  and  Standley  3129 
(Hb.  Field  223808).  ARIZONA:  Chiricahua  Mountains,  fields  and  sedi- 
ments, J.  C.  Blunter  1487  (Hb.  Field  242347;  Hb.  Gray;  Hb.  Mo.  85495; 
Hb.  N.  Y.);  Fort  Apache,  Rev.  PaulS.  Mayerhoff  88  (Hb.  Field  113427). 
WASHINGTON:  Spokane,  Frank  0.  Kreager  537  (Hb.  Gray);  Spokane, 
along  creek,  Sept.  i,  1899,  C.  V.  Piper  (Hb.  Gray);  West  Klickitat 
County,  sandy  banks  of  Columbia  River,  W.  N.  Suksdorf  1583  (Hb. 
Field  89751;  Hb.  Gray;  Hb.  Mo.  85499).  CALIFORNIA:  Los  Angeles, 
Dr.  Hasse  4695  (Hb.  N.  Y.).  SAN  Luis  POTOSI:  San  Luis  Potosi,  in 
sandy  places  about  the  city,  Dr.  J.  G.  Schajfner  388  (Hb.  Gray).  Sina- 
loa:  near  Mazatlan,  Rose,  Standley  and  Russell  14133  (Hb.  N.  Y.; 
Hb.  U.  S.  636993).  GUANAJUATO:  Guanajuato,  in  1891,  Prof.  A. 
Duges  (Hb.  Gray).  MORELOS:  near  Cuernavaca,  C.  G.  Pringle  7330 
(Hb.  Gray).  OAXACA:  Valle  de  Etla,  Rev.  Lucius  C.  Smith  783  (Hb. 
Gray).  CUBA:  Guines,  H.  A.  Van  Hermann  166  (Hb.  Field  170583). 

Moretti's  original  description  of  X.  italicum  is  very  full.  According 
to  his  own  account,  for  a  long  time  he  had  considered  his  species  to  be 
X.  echinatum  Murr.  and  had  sent  specimens  so  labeled  to  various  emi- 
nent botanists  such  as  De  Candolle,  Bertoloni  etc.  Finally  he  was  forced 
to  the  conclusion  that  the  species  was  distinct  from  X.  echinatum  Murr. 
and  so  he  described  it  as  new.  He  stated  numerous  characters  in  a 
minutely  detailed  way.  We  quote  his  description  of  the  fruit:  "Nux 
ovato-oblonga,  undique  aculeata,  aculeis  rigidis,  apice  simpliciter  un- 
cinatis,  singulis  undique  echinatis.  Rostra  bina,  patula,  uncinata, 
quorum  uncini  convergentes.  Styli  basi  laeviter  complanati,  hinc 
bifidi,  e  latere  interiori  uniuscuiusque  rostri  versus  extremitatem 
prodeuntes." 

Moretti's  plants  were  collected  in  several  localities  along  the  Po 
River  from  Turin  to  Pavia.  In  the  Bernhardi  Herbarium  (Hb.  Mo. 
85516)  there  exists  a  somewhat  fragmentary  and  immature  specimen 
with  the  inscription  "Xanthium  echinatum frequens  Tau- 


APRIL,  1919.     XANTHIUM — MILLSPAUGH  AND  SHERFF.  43 

rini."  This  is  clearly  one  of  Moretti's  original  specimens.  In  the 
De  Candolle  Herbarium  at  Geneva  there  exists  a  fine  mature  specimen 
collected  by  Moretti  in  the  vicinity  of  Pavia,  in  1819.  This  likewise 
had  been  labeled  Xanthium  echinatum  by  Moretti.1  It  matches  well 
the  Turin  specimen  from  the  Bernhardi  Herbarium  and  both  of  these 
specimens  agree  perfectly  with  the  plate  published  (from  a  specimen 
sent  by  Moretti)  by  Reichenbach  (loc.  tit.)  in  1826.* 

X.  varians  Greene,  while  somewhat  atypic  in  that  its  fruiting  prickles 
are  slightly  stouter,  is  easily  seen  to  be  a  form  of  this  species.  X. 
Macounii  Britton  is  best  considered  as  likewise  a  form  of  X.  italicum. 
Unfortunately,  the  single  type  specimen  on  which  the  description  of 
X.  Macounii  was  based  has  immature  fruits.  These  point,  however, 
to  a  somewhat  atypic,  rather  sparsely  aculeate  form  of  X.  italicum, 
such  as  may  be  found  growing  occasionally  among  plants  of  the  typical 
form.  Of  X.  glandulijerum  Greene  we  have  seen  two  specimens  of  the 
type  collection  (Hb.  Can.;  Hb.  Greene  19844).  These  would  seem  at 
first  to  be  closer  to  X.  echinatum  Murr.  But  the  size  and  shape  of  the 
achene  and  the  character  of  the  foliage  all  indicate  a  closer  affinity  with 
X.  italicum.  At  best,  X.  glandulijerum  is  probably  to  be  considered  as 
only  another  of  the  mutant  forms  produced  occasionally  by  X.  italicum. 

With  X.  italicum  must  be  placed  also  X.  commune  Britton,  originally 
described  from  Westport,  New  York.  The  type  specimen  of  X.  com- 
mune has  the  burs  somewhat  immature.  These  match  closely  those  of 
the  type  material  of  X.  glandulijerum  Greene.  We  have  seen  several 
cases  (e.  g.,  Greenman  537,  Hb.  Gray)  in  which  exactly  the  same  form  of 
burs  appeared  along  with  other  burs  that  were  topical  of  X.  italicum. 
But  whether  this  divergence  from  the  typical  form  was  due  to  hybridiza- 
tion or  to  mere  variation  we  are  unable  to  state.8 

18.   XANTHIUM  ACEROSUM  Greene,  Pittonia  4:   63.    1899. 

Caulis  flexuosus,  lineis  purpureis  longitudinalibus  saepe  maculatus. 
supra  scaber,  infra  fere  glabrescens,  verisimiliter  circum  4-9  dm.  altus, 
Folia  late  subcordato-ovata,  obtusa,  crenato-dentata,  utrinque  setulis 
minutis  adpressis  scabra,  petiolis  adjectis  0.7-2  dm.  longa,  petiolis 
laminis  subaequantibus.  Fructuum  (PI.  VII,  f.  *8;  PI.  IX,  ff.  22-24) 
corpus  cylindricum,  moderate  glanduloso-pubescens,  aculeis  subremotis 
armatum,  1.5-1.9  cm.  longum  et  6-7  mm.  crassum;  rostris  tenuibus, 
attenuatis,  molliter  pubescentibus,  subrectis  aut  irregulariter  incurvatis, 
ad  apicem  minime  hamosis,  7-8  mm.  longis;  aculeis  vix  numerosis, 

1  We  rely  upon  a  large  and  excellent  photograph  of  the  sheet,  furnished  us  through 
the  great  kindness  of  the  late  M.  Casimir  De  Candolle. 

JWe  have  seen  various  European  specimens  collected,  since  Moretti's  time,  in 
Italy,  Corsica,  Sardinia  etc.  Some  of  these  were  already  labeled  X.  italicum. 

1  For  distinctions  between  X.  italicum  and  X.  pennsylvanicum,  see  p.  34. 


44      FIELD  MUSEUM  OF  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

gracilibus,  remisse  fere  usque  ad  apicem  pilis  mollibus  longiusculis 
vestitis,  rectis  aut  subrectis,  ad  apicem  nunc  dimidia  parte  eorum 
hamosa,  nunc  vix  uno  aculeo  hamoso,  plerumque  6-9  mm.  longis. 

DISTRIBUTION:  New  York  (where  apparently  adventive) ;  Wisconsin, 
North  Dakota  and  Nebraska. 

SPECIMENS  EXAMINED:  NEW  YORK:  Whitehall,  Dresden  Trestle, 
Stewart  H.  Burnham  28  (Hb.  Gray).  WISCONSIN:  Brown  County, 
Preble,  Baird's  Creek,  Sept.  26, 1899,  /.  H.  Schuette  (Hb.  Gray;  Hb.  U.  S. 
751759;  the  latter  a  rather  immature  and  indistinctive  specimen). 
NORTH  DAKOTA:  near  Fargo,  Sept.  4,  1893,  Edward  L.  Greene  (Hb. 
Greene  19835; —  type) ;  Minot,  along  Souris  River,  Dr.  J.  Lunell  80  (Hb. 
Gray);  Burleigh  County,  Bismarck,  Aug.  23,  1913,  idem  (Hb.  Greene 
23707).  NEBRASKA:  Red  Cloud,  Rev.  J.  M.  Bates  4747  (Hb.  Gray). 

It  is  with  some  hesitation  that  this  species  is  here  retained.  The 
fruiting  burs,  when  slightly  immature,  resemble  those  of  X.  italicum. 
When  fully  ripe,  they  appear  to  be  intermediate  between  those  on  cer- 
tain forms  of  X.  pennsylvanicum  Wallr.  and  those  on  certain  forms  of 
X.  speciosum  Kearney.  The  brown,  ripe  burs  have  a  body  more  or 
less  narrowly  cylindrical;  the  prickles  are  mostly  long  and  very  delicate; 
their  hairs  are  soft  and  fine.  However,  as  the  specimens  examined  agree 
very  well  among  themselves,  interference  with  the  status  of  the  species 
seems  scarcely  wise  or  desirable  at  the  present  time. 

19.   XANTHIUM  OVIFORME  Wallr.,  Beitr.  Bot.  i11:    240.    1844. 
X.  silphiifolium  Greene,  Pittonia  4:    60.    1899. 

Caulis  simplex,  infra  levis,  supra  scabridus,  3-7  dm.  altus.  Folia 
membranacea,  indivisa,  deltoideo-ovata,  interdum  vix  trinervia, 
inaequaliter  sinuato-dentata,  utrinque  concoloria  et  setulis  minutis 
adpressis  albidis  aspera,  ad  basim  vel  orbiculata  vel  truncata  vel 
cordata,  petiolis  adjectis  0.7-2  dm.  longa,  petiolis  laminis  subaequan- 
tibus.  Fructus  (PI.  VII,  f.  19;  PI.  X,  ff.  1-3)  non  multi,  demum  maximi, 
plerumque  singulatim  dispositi;  fructuum  corpore  oblongo-ovato, 
glanduloso-hispido  aut  rariter  glabriusculo,  aculeis  armato,  demum 
circum  2  cm.  longo  et  1.2  cm.  crasso;  rostris  validis,  crassis,  hispidis, 
supra  incurvatis,  ad  apicem  valde  uncinatis,  circum  8  mm.  longis; 
aculeis  remotis  aut  subremotis  (aut  fere  confertis),  validis,  arcuatis  et 
corniformibus,  fere  usque  ad  apicem  ferrugineo-hispidis  (saltern  ad 
tergum  et  latera),  ad  apicem  valde  hamosis,  ad  faciem  ventralem  infe- 
rioribus  plerumque  canaliculatis,  (5-)  7-10  mm.  longis. 

DISTRIBUTION:  Washington  and  probably  Oregon;  also  adventive, 
formerly  at  least,  in  southwestern  Illinois. 

SPECIMENS  EXAMINED:  WASHINGTON:  Wawawai,  C.  V.  Piper  3575 
(Hb.  Gray);  Kittitas  County,  Rock  Island,  along  water-courses, 
Sandberg  and  Leiberg  446  (Hb.  Gray);  West  Klickitat  County,  Sept.  28, 
1883,  sandy  banks  of  the  Columbia  River,  W.  N.  Suksdorf  (Hb.  Field 


APRIL,  1919.     XANTHIUM — MILLSPAUGH  AND  SHERFF.  45 

97447  and  211249;  cotypes  of  X.  silphiifolium  Greene) ;  without  locality, 
in  1879,  idem  (Hb.  Gray);  West  Klickitat  County,  bottom  lands  of  the 
Columbia  River,  idem  189  (Hb.  Gray).  ILLINOIS:  East  St.  Louis, 
banks  of  the  Mississippi  River,  Sept.,  1847,  Dr.  George  Engelmann  (Hb. 
Mo.  85552;  form  close  to  X.  speciosum  Kearney);  cultivated  by  Asa 
Gray,  in  botanical  garden,  Cambridge,  Massachusetts,  Oct.,  1848,  from 
171  and  ifia  of  Dr.  George  Engelmann,  collected  presumably  in 
September,  1847,  at  East  St.  Louis,  111.,  with  the  preceding  specimen 
(2  sheets  in  Hb.  Gray;  more  typical  than  Engelmann's  own  specimen). 

Greene  (loc.  tit.),  in  proposing  nine  species  of  Xanthium  as  new, 
among  them  X.  silphiifolium,  laid  no  claims  to  a  very  profound  knowl- 
edge of  the  genus  as  a  whole.  Thus,  with  reference  to  Wallroth's  mono- 
graphic treatment  of  Xanthium,  he  says:  "At  present  I  know  nothing 
as  to  what  his  X.  laevigatum,  pungens,  pennsylvanicum,  xanthocarpum 
or  oviforme  are.  Presumably,  however,  they  all  belong  to  the  Atlantic 
slope  of  the  continent.  Little  or  nothing  was  known  of  this  genus  as 
represented  west  of  the  Mississippi  in  the  year  1842  [sic].  As  all  the 
following  are  from  far-western  regions,  I  shall,  in  naming  them  as  new, 
incur  small  risk  of  becoming  a  manufacturer  of  synonyms." 

Regarding  three  of  these  species,  viz.  X.  pungens,  X.  pennsylvanicum 
and"X.  xanthocarpum,"  there  need  be  no  doubt  as  to  the  forms  referred 
to  by  Wallroth  (cf.  pp.  22,  31  and  15).  Regarding  X.  laevigatum,  we  our- 
selves are  unable  as  yet  to  reach  positive  conclusions.  The  case  of  X. 
oviforme,  however,  lends  itself  to  very  definite  treatment.  Wallroth's 
description  of  this  species  is  decisive  and  clear.  In  speaking  of  the 
fruits  he  says  (loc.  tit.) :  "fructibus  sessilibus  solitariis  utrinque  aequali- 
ter  rotundatis  oviformibus  (maximis),  aculeis  confertis  validis  corni- 
formibus  basi  pilis  articulatis  ferrugineis  densis  vestitis  cum  rostris 
intus  contractis  teretibus  figura,  vestitu  et  longitudine  subconformibus 
deliquescendo  veluti  obliteratis."  We  have  also  his  footnotes  regarding 
the  fruits.  The  first  one  says:  "5)  eifo"rmige,  in  Vergleich  zur  Pflanze 
(d.h.  dem  vorliegenden  Probestucke)  sehr  grosse,  mit  den  Stacheln 
dem  Umfang  einer  kleinen  Wallnuss  oder  Musskatennuss  gleichende 
Frucht."1 

1  Two  other  footnotes  in  connection  with  the  fruits  are  given  by  Wallroth.  We 
reproduce  them  verbatim  herewith:  "6)  besonders  stark  ausgebildete,  dicht- 
stehende,  2'"  lange  Stacheln,  welche  bis  uber  die  Halfte  mit  dicht-und  abstehenden, 
gegliederten  Haaren  umstarrt  sind,  am  oberen  Theile  aufwarts,  in  der  Mitte  etwas 
abwarts  und  am  Grunde  ruckwarts  gerichtet  sind  und  den  ganzen  Fruchtkorper 
allenthalben  dich  und  gleichmassig  umstarren; 

"  7)  mit  den  Stacheln  fast  gleichformige,  nur  doppelt  so  starcke,  nach  oben  rinnen- 
fdrmig  ausgehohlte  Stacheln,  welche  wegen  gegenseitiger  Aehnlichkeit  mit  den  Sta- 
cheln gleichsam  zu  verschwinden  oder  im  Vergleich  mit  anderen  Arten  zu  fehlen 
scheinen." —  The  grooved  ventral  surfaces  exhibited  by  certain  of  the  large  basal 
prickles  on  the  fruits  of  this  species  seem  indeed  an  unique  character. 


46     FIELD  MUSEUM  OF  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

A  comparison  of  Wallroth's  Latin  description  with  the  others  in  his 
monograph  shows  two  outstanding  features  for  his  X.  oviforme.  The 
fruits  were  very  large  and  were  covered  with  strong,  horn-shaped  prickles, 
these  densely  clothed  at  their  base  with  jointed,  reddish  hairs.  Further- 
more, Wallroth  based  his  species  directly  upon  Hooker's  Xanihium 
canadense  from  North  America  ("X.  Canadense  Hook,  in  lit.  (herb, 
general  berol.),  nee  Herm.,  Mill,  et  Linn.  Angeblich  in  Nordamerika 
und  vermuthlich  in  Canada."). 

Thus,  Wallroth  had  seen  a  plant  in  Berlin  labeled  "X.  canadense" 
by  Hooker,  but  which  appeared  distinct  from  all  other  specimens 
because  of  its  mammoth  burs  and  their  horn-shaped  prickles.  On 
reference  to  Hooker's  Flora  Boreali-Americana,  a  work  published  in 
1840  and  which  Wallroth  appears  not  to  have  seen,  we  find  the  basis  of 
Wallroth's  species.  Hooker  (loc.  cit.  308),  instead  of  giving  an  extended 
range  or  list  of  stations  as  in  the  case  of  many  other  species,  gave 
merely,  "Hab.  Canada?  North-West  coast  of  America.  Douglas." 
So  the  plant  determined  by  Hooker  as  X.  canadense  was  a  plant  collected 
by  Douglas  along  the  northwest  coast  of  (North)  America.1  But  it  was 
in  this  same  region  that  the  type  of  X.  silphiifolium  Greene  was  ob- 
tained. Greene's  type  was  collected  by  Suksdorf,  on  the  banks  of  the 
Columbia  River,2  September,  1883.  While  this  type  itself  (in  Hb.  U.  S.) 
is  at  present  inaccessible  to  us,  we  have  seen  the  two  excellent  cotypes 
in  the  Herbarium  of  Field  Museum  and  also  the  two  other  specimens 
by  Suksdorf  in  Gray  Herbarium.  These  all  agree  well  with  each  other 
in  having  large,  coarse  burs,  with  very  strong,  elongate,  reddish-hispid, 
horn-shaped  (arcuate),  hooked  prickles  and  somewhat  similar  beaks; 
the  lower  prickles  on  each  bur  tend  to  be  strongly  grooved  upon  the 
ventral  face.  The  specimen  collected  by  Suksdorf  on  bottom  lands  of 
the  Columbia  River  (no.  189)  is  particularly  instructive.  It  is  accom- 
panied by  one  mature  bur,  much  larger  than  the  rest,  a  bur  such  as 
most  collectors  might  shrink  from  trying  to  press.  This  bur  is  really  of 
gigantic  proportions,  having  a  size  observed  by  us  so  far  in  only  two 
other  species  (X.  campestre  and  X.  speciosum).  The  body  proper  is 
2.3  cm.  long  and  about  i  cm.  thick.  The  prickles  and  beaks  measure 
from  8  mm.  to  10  mm.  in  length,  giving  the  bur  a  total  expanse  of  3.9 
cm.  in  length  and  about  2.8  mm.  in  width. 

Without  question,  it  was  this  large-fruited  form  of  Xanthium  that 

1  Had  Hooker  seen  plants  of  this  species  from  other  collections  it  is  clear  that  he 
would  have  cited  them,  since  his  citations  of  range  appear  in  each  case  to  be  as 
complete  as  his  data  at  that  time  would  permit. 

2  An  examination  of  Hooker's  text  shows  that  a  large  proportion  of  the  other 
Douglas  plants  studied  by  Hooker  had  likewise  come  definitely  from  the  banks  of 
the  Columbia  River. 


APRIL,  1919.     XANTHIUM  —  MILLSPAUGH  AND  SHERFF.  47 

was  the  basis  of  Wallroth's  X.  oviforme  and  the  identity  of  the  species 
is  thus  seen  to  be  settled  too  clearly  to  permit  of  its  name  being 
displaced  by  the  more  recent  name  X.  silphiifolium}' 

20.    XANTHIUM  SPECIOSUM  Kearney,  Bull.  Tor.  Bot.  Club  24:  574, 

1897. 
X.  bubalocarpon  Bush,  Kept.   Missouri  Bot.   Gard.  17:     123, 


Caulis  erectus,  robustus,  ramosus,  ad  basim  demum  2.5  cm.  crassus, 
plus  minusve  (infra  obtuse  et  supra  acute)  quadrangulatus,  supra  lineis 
purpureis  maculatus,  papilloso-scabridus  praesertim  supra,  1-1.5  m- 
altus.  Folia  late  triangulato-ovata,  obtuse  et  non  profunde  3~5-lobata, 
dentata,  crassiuscula,  ad  basim  cordata,  utrinque  setulis  aut  papillis 
minutis  adpressis  scabra,  petiolis  adjectis  1-3.5  <"&«  longa  et  0.8-2.2  dm. 
lata,  petiolis  laminis  subaequantibus.  Fructus  (PI.  VII,  f.  20;  PI.  X, 
ff  .  4-6)  maximi,  ovoidei  aut  conici;  corpore  ovato-cylindrico,  vix  aspecta- 
bili,  glanduloso-pubescenti,  aculeis  armato,  demum  circum  2-2.3  mm- 
longo  et  7-8  mm.  crasso;  rostris  attenuatis,  hispidis,  subrectis  aut 
incurvatis,  ad  apicem  hamosis,  6-n  mm.  longis;  aculeis  confertis,  sub- 
tenuibus,  besse  inferiore  aut  dimidio  inferiore  hispido,  versus  apicem 
levibus,  ad  apicem  hamosis,  plerumque  7-9  mm.  longis;  toto  fructu 
(aculeis  et  rostris  adjectis)  demum  3-4  cm.  longis  et  2-2.5  (~3  ex  descrip- 
tionibus  Kearneyi  et  Bushii)  cm.  latis. 

DISTRIBUTION:  Tennessee  to  South  Dakota,  Texas  and  Mexico; 
adventive  in  Maine  and  Vermont.3 

SPECIMENS  EXAMINED:*  MAINE:  North  Berwick,  wool-waste  heap, 
Sept.,  1895,  John  C.  Parlin  (Hb.  Gray).  TENNESSEE:  Cocke  County, 
between  Paint  Rock  and  Del  Rio,  along  French  Broad  River,  Thos.  H. 
Kearney,  Jr.,  785  (Hb.  Greene  19829;  Hb.  Mo.  85550;  Hb.  N.  Y.; 
cotypes).  MISSOURI:  Cass  County,  roadside,  prairie,  Aug.,  1869,  G.  C. 

1  Since  the  above  was  written,  we  have  been  very  fortunate  in  receiving  from 
the  Herbaria  of  the  British  Museum  of  Natural  History  and  the  Royal  Botanical 
Gardens  at  Kew,  excellent  photographs  of  the  Douglas  plants.   Our  conclusions,  as 
presented  above,  are  seen  to  be  confirmed  most  emphatically.  Both  specimens  match 
precisely  the  Suksdorf  material  of  X.  silphiifolium.   The  inscription  on  the  British 
Museum  sheet,  as  copied  for  us,  reads,  "X.  strumarium  Willd.  Sandy  island  and 
banks  of  the  Columbia  Douglas  1825  Xanthium  canadense  Spreng.   Hook  Fl.  Bor.- 
Am.  i.  p.  308."  That  upcn  the  sheet  at  Kew  (a  sheet  originally  in  Bentham's  private 
herbarium)  reads,  "Xanthium  canadense  Spr.  Hook  Fl.  Bor.  Am.  I.  308.  Am.  bor. 
occ.    Douglas  1829  [sic]  X.  oviforme  Wallr.  cotype." 

2  Piper  (Contrib.  U.  S.  Nat.  Herb.  1  1  :   550.    1906)  has  referred  X.  silphiifolium 
Greene  to  this  species.    But,  as  will  be  apparent  from  the  foregoing  paragraphs 
(C/.  X.  oviforme,  p.  44)  if  X.  silphiifolium,  which  is  synonomous  with  X.  oviforme, 
shall  subsequently  be  proved  conspecific  with  X.  speciosum,  then,  by  the  same  proof, 
X.  speciosum  will  have  been  shown  to  be  synonomous  with  X.  oviforme. 

*  Cf.  footnote  i,  p.  27. 

4  We  have  seen  two  specimens  by  H.  Eggert,  one  at  least  from  Illinois  (pre- 
sumably at  East  St.  Louis),  collected  Sept.  13,  1874  (Hb.  Gray;  Hb.  Mo.  85381). 
These  appear  to  be  X.  speciosum,  but  the  prickles  are  subremote  and  rather  stout  and 
suggest  X.  oviforme  Wallr.  very  strongly. 


48      FIELD  MUSEUM  or  NATURAL  HISTORY — BOTANY,  VOL.  IV. 

Broadhead  (Hb.  Mo.  85553).  ARKANSAS:  Fulton,  B.  F.  Bush  2408 
(Hb.  Mo.  85375).  SOUTH  DAKOTA:  Deadwood,  waste  ground,  alt.  1430 
m.,  John  Murdoch,  Jr.,  4334  (Hb.  Gray).  KANSAS:  Kiowa  County,  low 
ground,  A.  S.  Hitchcock  726  (Hb.  Gray;  Hb.  Mo.  85525).  OKLAHOMA: 
Hugo,  moist  limestone  soil,  E.  J.  Palmer  9015  (Hb.  Mo.  794481). 
TEXAS:  Dallas,  prairie,  B.  F.  Bush  1185  (Hb.  Gray;  Hb.  Mo.  85380; 
type  specimens  of  X.  bubalocarpon  Bush);  Pease  River,  near  Vernon, 
salt  bottoms,  Sept.  18,  1903,  H.  Eggert  (Hb.  Mo.  85558  and  85559); 
Dallas,  Oct.  10,  year  not  stated,  /.  Reverchon  (Hb.  Mo.  85557);  Coombs 
Branch,  Aug.  24,  1901,  idem  (Hb.  Mo.  85556  and  85562);  Coombs 
Branch,  Oct.  9,  year  not  stated,  idem,  (Hb.  Mo.  85479) ;  Dallas,  prairie, 
Aug.  30,  1901,  idem  (Hb.  Gray;  Hb.  Mo.  85378);  Dallas,  prairie,  idem 
2580  A  (Hb.  Mo.  85379);  Luck's  Mill,  Aug.  25,  year  not  stated,  idem 
(Hb.  Mo.  85560  and  85561);  Oak  Cliff,  wastes,  Aug.  30,  1901,  idem 
(Hb.  Mo.  85376  and  85377). l 

While  appearing  in  rare  cases  to  intergrade  or  perhaps  hybridize 
with  X.  oviforme  Wallr.,  X.  speciosum  seems,  nevertheless,  on  the  whole 
to  be  worthy  of  retention  as  a  distinct  species.  It  is  apparently  best 
distinguished  from  that  species  by  the  closer,  more  slender  and  less 
arcuate  prickles,  which  do  not  suggest  horns,  and  by  a  tendency  of  the 
entire  involucre,  when  mature,  toward  a  yellowish  or  yellowish-brown 
color  rather  than  toward  the  dark-reddish  color  shown  in  X.  oviforme. 

The  several  sheets  of  type  material  (Kearney  785)  that  we  have 
examined  are  of  a  slightly  immature  stage  and  the  burs  are  not  fully 
ripened.  But  Kearney  (loc.  tit.}  described  the  burs  as  "2.5-4  cm.  long, 
2.5-3  cm'  wide  (including  the  prickles) "  and,  as  some  of  the  slightly 
immature  burs  are  observed  by  us  on  the  type  material  to  have  become 
3.5  cm.  long  and  2.5  cm.  wide  (including  the  prickles),  it  is  certain  that 
Kearney's  measurements  correctly  represent  the  mature  fruits. 

In  describing  his  X.  bubalocarpon,  Bush  (loc.  tit.}  stated:  "This 
very  distinct  species  is  more  nearly  related  to  X.  speciosum  Kearney, 
but  is  easily  distinguished  from  that  species  by  the  much  larger  burs 
which  are  of  an  entirely  different  shape."  However,  on  reading  his 
description,  we  find  given  the  measurements  "  2.5-4  cm.  long,  including 
the  prickles."  It  is  seen  that  these  measurements  are  practically 
identical  with  those  given  by  Kearney  for  X.  speciosum.  And,  indeed, 
when  we  compare  the  excellent  type  material  of  X.  bubalocarpon  (Bush 
1185)  with  that  of  X.  speciosum,  we  can  detect  no  specific  difference. 

1  We  have  seen  no  typical  material  of  X.  speciosum  from  Mexico.  Certain  some- 
what anomalous  forms  from  there  appear,  however,  to  be  best  regarded  as  belonging 
to  this  species  (e.g.,  J.  N.  Rose  2433,  near  San  Juan  Capistrano,  Zacatecas,  Hb.  U.  S. 
301344;  Rose,  Painter  and  Rose  0032,  near  Tehuacan,  Puebla,  Kb*  U.  S.  453446). 


APRIL,  1919.     XANTHIUM — MILLSPAUGH  AND  SHERFF.  49 

The  two  are  well  connected,  furthermore,  by  the  various  other  specimens 
of  differing  stages  of  maturity  examined  by  us  and  cited  above. 

21.    XANTHIUM  CAMPESTRE  Greene,  Pittonia  4:    61.    1899. 

Caulis  saepe  lineis  purpureis  brevibus  maculatus,  supra  scabridus, 
5-8  dm.  altus.  Folia  subcrassa,  subdeltoidea,  dentata  aut  serrata,  non 
perspicue  lobata,  ad  basim  truncata  aut  cordata,  supra  scabra,  infra 
scabro-pubescentia,  petiolis  adjectis  6-17  cm.  longa,  petiolis  laminis 
subaequantibus.  Fructus  (PI.  VII,  f.  21;  PI.  X,  ff.  7-8)  maximi,  maxi- 
mam  partem  singulatim  dispositi,  ovoideo-conici;  corpore  non  saepe 
aspectabili  sed  aculeis  plerumque  numerosis  et  densissimis  armato, 
demum  circ.  2.3-2.6  cm.  longo  et  1-1.3  cm.  crasso;  rostris  late  diver- 
gentibus,  infra  crassis  et  pubescentibus,  supra  glabratis  et  tenuiter 
hamosis,  6-7  mm.  longis;  aculeis  teretibus,  arcuatis,  infra  (demum 
ferrugineo-)  hispidissimis,  supra  glabris  et  ad  apicem  hamosis,  circum 
5  mm.  longis;  toto  fructu  (aculeis  et  rostris  adjectis)  demum  2.8-3.5  cm- 
longo  et  2-2.5  cm-  lato. 

DISTRIBUTION:   California. 

SPECIMENS  EXAMINED:  CALIFORNIA:  Chico,  June  27, 1890,  Edward 
L.  Greene  (Hb.  Greene  19837;  type);  Chico-Hamilton  Road,  9.5  km. 
northwest  of  Chico,  A.  A.  Heller  11629  (Hb.  Calif.  179073;  Hb.  Field 
426983;  Hb.  Gray;  Hb.  Greene  51204;  Hb.  Mo.  748145;  Hb.  N.  Y.,  a 
more  mature  specimen,  with  the  burs  just  turning  reddish  in  color.) 

This  species  is  distinguished  from  most  others  by  the  great  size  of  its 
burs,  these  coming  to  have,  when  well-developed,  an  expanse  (including 
the  beaks  and  prickles)  of  about  3.5  cm.  in  length  and  2.5  cm.  in  width. 
In  Greene's  type  specimen,  the  prickles  are  remote  enough  to  permit  a 
view  of  the  body  of  the  bur.  The  several  somewhat  immature  speci- 
mens by  Heller  have  the  prickles  more  densely  grouped  together,  leav- 
ing the  body  mostly  concealed.  The  burs  have  a  decidedly  yellowish- 
green  color  until  nearly  mature,  when  they  turn  to  a  reddish  color, 
rather  closely  resembling  those  of  X.  oviforme  Wallr. 


INDEX 


Acanthoplia  Wallr.  14 
Acanthoxanthiura  DC.  14 
A  canthoxanthium 

spinosum  Fourr.  14 
Anoplia  Wallr.  15 
Campy lorrhyncha  Wallr.  15 
Euxanthium  DC.  15 
Lappa  canadensis 

minor i  Ray  26 
Orthorrhyncha  Wallr.  15 
Xanthium  L.  12 

abyssinicum  Wallr.  16 

acerosum  Greene  9,  43 

acutilobum  M.  &  S.  35 

acutum  Greene  31,  9,  33,  34,  35 

affine  Greene  31,  9,  33,  35 

ambrosioides  H.  &  A.  17 

americanum  Walt.  20,  10,  22,  23 

antiquorum  Wallr.  16,  17,  20 

arcuatum  M.  &  S.  25 

australe  M.  &  S.  37 

brasilicum  Velloz.  37 

brevirostre  Wallr.  16,  17 

bubalocarpon  Bush  47,  48 

californicum  Greene  31,  9,  33,  34,  35, 
36 

calvum  M.  &  S.  35 

campestre  Greene  49,  39 

canadense  Mill.  20,  17,  46 

carolinense  Dill.  17 

Cavanillesii  Schouw.  40 

cenchroides  M.  &  S.  30 

chinense  Mill.  17,  10,  23,  25,  26,  27, 
32,  37,  39,  40 

commune  Britt.  40,  29,  41,  43 
Woptoni  Cockll.  28 

crassifolium  M.  &  S.  35 

crassum  Raf.  16 

cuneatum  Moen.  26 

curyescens  M.  &  S.  25 

cylindricum  M.  &  S.  23,  9 

discolor  Wallr.  16,  17,  21 

echinatum  Murr.  38,  10,  22,  23,  33, 
42,43 


Xanthium 

elatius  a  majus  americanum  Moris.  26 
eriocarpon  Wallr.  17 
glabratum  Britt.  17 
glanduliferum  Greene  40,  9,  43 
globosum  Shull  23,  9,  10 
homothalamum  Spr.  37 
inaequilaterum  DC.  17 
inflexum  Mack.  &  Bush  30 
italicum  Mor.  40, 10,  27, 33, 34, 38, 43 
laevigatum  Muhl.  45 
leptocarpum  M.  &  S.  28,  26,  27 
leucocarpon  Wallr.  17 
longirostre  Wallr.  17,  22,  37 
Macounii  Britt.  40,  43 
macrocarpum  DC.  26,  10,  27 

glabratum  DC.  17 
maculatum  Raf.  38,  16,  39 
majus  canadense  Herm.  26 
occidentale  Bertol.  17.  22.  23 
oligacanthum  Piper  28 
orientale  L.  26,  10,  16,  20,  25,  27,  39 
oviforme  Wallr.  44,  47,  48,  49 
palustre  Greene  36 
pennsylvanicum  Wallr.  31,  10,  22, 

25,  36,  39,  4i,  44,  45 

eglandulosum  Wallr.  31,  34,  32 

glandulosum  Wallr.  31,  34 
pensylvanicum  Wallr.  31 
priscorum  Wallr.  17,  1 6 
pungens  Wallr.  17,  22,  23,  45 
riparium  Lasch.  39 
Roxburghii  Wallr.  16,  17 
saccharatum  Wallr.  31,  34 
silphiifolium  Greene  44,  45,  46,  47 
speciosum  Kearn.  47,  27,  44 
spinosum  L.  14,  10 
strumarium  L.  16,  10,  17,  22 

antiquorum  Ball.  16 

brasilicum  Bak.  37 
undulatum  Raf.  16 
varians  Greene  40,  43 
Wootoni  Cockll.  28 
xanthocarpon  Wallr.  14,  15,  45 


PLATE  VII. 

P.  I.   X.  spinosum  L.  Eggert  (Hb.  Mo.  720835). 

F.  2.   X.  strumarium  L.  Brandegee  (Hb.  Calif.  131246). 

F.  3.  X.  chinense  Mill.  Greenman  47  (Hb.  Field  189512;  topotype;  atypic  in  hav- 
ing prickles  slightly  pubescent  at  base.) 

F.  4.   X.  cyhndricum  Millsp.  and  Sherff.  Small  and  Huger  (Hb.  Field  401312;  type). 

F.  5.  X.  globosum  Shull.  Shull  (Hb.  Field  477328;  lineal  descendant  of  type  mate- 
rial). 

F.  6.   X.  arcuatum  Millsp.  and  Sherff.  Lucy  (Hb.  Field  4953;  type). 

F.  7.   X.  curvescens  Millsp.  and  Sherff.  Eggleston  1420  (Hb.  Gray;  type). 

F.  8.   X.  leptocarpum  MiJJsp.  and  Sherff.   Jones  (Hb.  Field  430860;  type). 

F.  9.  X.  Wootoni  Cockll.  ex  De  Vries.  T.  D.  A.  Cockerell,  Las  Vegas,  New  Mexico, 
Oct.  4, 1901  (Hb.  N.  Y.;  authentic  material  from  author). 

F.  10.   X.  cenchroides  Millsp.  and  Sherff.  Reverchon  2332  (Hb.  Mo.  85563;  type). 

F.  ii.   X.  inflexum  Mack,  and  Bush.   Bush  1916  (Hb.  Mo.  85520;  type  material). 

F.  12.   X.  pennsylvanicum  Wallr.   Lansing  3532  (Hb.  Field  346590). 

F.  13.   X.  calvum  Millsp.  and  Sherff.   Baker  1760  (Hb.  Calif.  131236;  type). 

F.  14.   X.  palustre  Greene.  Walker  973  (Hb.  Calif.  128022). 

F.  15.   X.  australe  Millsp.  and  Sherff.   Palmer  275  (Hb.  U.  S.  463216;  type). 

F.  16.  X.  echinatum  Murr.  Miss  M.  E.  Blatchford,  Prouts  Neck,  Me.,  Sept.,  1898 
(Hb.  Gray). 

F.  17.   X.  italicum  Mor.  B.  L.  Robinson,  Springfield,  Vt.,  Sept.  16,  1899  (Hb.  Gray). 

F.  1 8.   X.  acerosum  Greene.  Lunell  80  (Hb.  Gray). 

F.  19.   X.  oviforme  Wallr.   Suksdorf  189  (Hb.  Gray). 

F.  20.  X.  speciosum  Kearn.  Bush  1185  (Hb.  Mo.  85380;  type  material  of  X. 
bubalocarpon  Bush). 

F.  21.   X.  campestre  Greene.   Heller  11629  (Hb.  Gray;  topotype). 


FIELD  MUSEUM  OF  NATURAL  HISTORY. 


BOTANY  VOL.  IV,  PLATE  VII. 


FRUITS  OF  XANTHIUM     (Natural  size) 


PLATE  VIII. 

X.  spinosum  L. 

F.  i.    C.  R.  Orcutt,  Port  Harford,  Calif.,  Nov.  23,  1886  (Hb.  Mo.  85586). 

F.  2.    Heller  12655  (Hb.  Mo.  802945). 

F.  3.    Griffiths  7344  (Hb.  Mo.  85583). 
X.  strumarium  L. 

F.  4.   Hb.  Schlagintweit,  drained  lake  basin  of  Kashmir,  vicin.  Srinagger,  prov. 
Kashmir,  India,  Oct.  2-20,  1856  (Hb.  Gray). 

F.  5.   T.  Thomson,  Plan.  Ganget.  Sup.,  India  Orient.    (Hb.  Gray). 

F.  6.   Fernald,  Crescent  Beach,  Revere,  Mass.,  Oct.  20,  1912  (Hb.  Gray). 

F.  7.   W.  Schirnper  1343,  in  agris  Sorghi  pr.  Sabra  Abyssinia  (Hb.  Gray;  cotype 
of  X,  abyssinicum  Wallr.). 

F.  8.   Kotschyi  iter  nubicum  319,  ad  ripas  Nili  albi  prope  Chartum  in  provincia 

Sennar  (Hb.  Gray;  cotype  of  X.  antiquorum  Wallr.). 
X.  chinense  Mill. 

F.  9.    Rose,  Fitch  and  Russell  4351  (Hb.  U.  S.  760483,  topotype  of  X.  occi- 
dentale  Bertol.). 

F.  10.    Greenman  47  (Hb.  Field  189512,  topotype). 

F.  ii.    Brown  and  Britton  374  (Hb.  Field  203890). 

F.  12.    Bush  1348  (Hb.  Mo.  85428). 

F.  13.    Phelps  989  (Hb.  Gray). 

Ff.  14  and  15.    Anonymous  (Hb.  Fla.  Agricult.  Coll.  no.  1279  in  Hb.  Field, 

no.  234909). 
X.  cylindricum  Millsp.  and  Sherff. 

Ff.  16,  17  and  18.   Small  and  Huger  (Hb.  Field  401312,  type). 

Ff.  19  and  20.    (Hb.  N.  Y.,  cotype). 
X.  globosum  Shull. 

F.  21.    Shull  (Hb.  Field  477328,  lineal  descendant  of  type  material). 

Ff.  22  and  23.    Shull  (Hb.  Field  477326,  topotype  identical  with  type). 
X.  arcuatum  Millsp.  and  Sherff. 

Ff.  24,  25  and  26.   Lucy  (Hb.  Field  4953,  type). 
X.  curvescens  Millsp.  and  Sherff. 

Ff.  27,  28  and  29.   Eggleston  1420  (Hb.  Gray,  type). 
X.  leptocarpum  Millsp.  and  Sherff. 

Ff.  30,  31  and  32.   Jones  (Hb.  Field  430860,  type). 
X.  Wootoni  Cockll.  ex  De  Vries. 

F.  33.    Deane,  South  Boston,  Mass.,  Oct.  4,  1909  (Hb.  Williams  in  Hb.  Gray). 

F.  34.   Horner  B  272  (Hb.  Gray). 

F.  35.    Piper  (Hb.  N.  Y.,  cotype  of  X.  oligacanthum  Piper). 

F.  36.    Cockerell  (Hb.  Gray,  author's  material). 
X.  cenchroides  Millsp.  and  Sherff. 

Ff.  37  and  38.   Reverchon  2332  (Hb.  Mo.  85564,  cotype). 

F.  39.    Reverchon  2332  (Hb.  Mo.  85563,  type). 


FIELD  MUSEUM  OF  NATURAL  HISTORY. 


BOTANY  VOL.  IV.  PLATE  VIII. 


2        3 


10 


II        12         13 


16     17      18 


24. 


25          26 


3°      31 


20 


21 


22       23 


28 


27 


29 


33 


34     35 


37  38 

FRUITS  OF  XANTHIUM    (Natural  size) 


US*  ART 

UNIVCESITY  Of  ILLINOIS 
URBANA 


PLATE  IX. 

X.  inflexum  Mack,  and  Bush. 

F.  i.   Bush,  1916  (Hb.  Gray,  type  material). 

F.  2.   Engelmann  (Hb.  Mo.  85551). 

F.  3.   Bush  1806  (Hb.  Mo.  85522). 

F.  4.   Bush  1806  (Hb.  Gray). 
X.  pennsylvanicum  Wallr. 

F.  5.   Greene  (Hb.  Greene  19822;  type  of  X.  calif ornicum  Greene). 

F.  6.   Sanford  (Hb.  Greene  19819,  type  of  X.  acutum  Greene). 

F.  7.   Reverchon  2589  (Hb.  Mo.  85546). 

F.  8.    Suksdorf  1584  (Hb.  Mo.  85374;  cotype  of  X.  affine  Greene). 

F.  9.   Lansing  3532  (Hb.  Field  346590). 

F.  10.   Heller  7550  (Hb.  N.  Y.). 
X.  calvum  Millsp.  and  Sherff. 

Ff.  ii  and  12.   Baker  1760  (Hb.  Calif.  131236,  type). 
X.  palustre  Greene. 

F.  13.   Greene  (Hb.  Greene  19834,  type  material). 

F.  14.   Greene  (Hb.  Greene  10833,  type  material). 

F.  15.  Walker  973  (Hb.  Calif.  128022). 
X.  australe  Millsp.  and  Sherff. 

F.  1 6.    Palmer  275  (Hb.  U.  S.  463216,  type). 

F.  17.   Dr.  Mertens,  Valparaiso,  Chile  (ex  Hb.  Acad.  Petrop.,  in  Hb.  Gray). 

F.  18.   Morong  807  (Hb.  N.  Y.): 
X.  echinatum  Murr. 

F.  19.   Sturteyant  (Hb.  Mo.  85500). 

F.  20.   Victorin  1056  (Hb.  Gray). 

F.  21.   Miss  M.  E.  Blatchford,  Prouts  Neck,  Me.,  Sept.,  1898  (Hb.  Gray). 
X.  acerosum  Greene. 

F.  22.   J.  H.  Schuette,  Baird's  Creek,  Preble,  Brown  County,  Wis.,  Sept.  26, 1899 
(Hb.  Gray). 

F.  23.   Burnham  28  (Hb.  Gray). 

F.  24.   Lunell  80  (Hb.  Gray). 
X.  italicum  Mor. 

F.  25.    Suksdorf  1583  (Hb.  Field  89751,  cotype  of  X.  varians  Greene). 

F.  26.    Macoun  11415  (Hb.  Can.  11415,  type  of  X.  Macounii  Britton). 

F.  27.    Macoun  10910  (Hb.  Can.  10910,  type  material  of  X.  glanduliferum 
Greene). 

F.  28.    Sherff  3081  (Hb.  Field  480739,  matching  fruits  on  Moretti's  specimen  in 
Hb.  De  Candolle). 

F.  29.    Bruyas,  gravelly  fields  along  banks  of  the  Arc  River,  Aix  Bouches-du- 
Rhone,  France,  Sept.  27,  1884  (Hb.  Field  331608). 

F.  30.   Rose  and  Fitch  17507  (Hb.  U.  S.  760583). 


FIELD  MUSEUM  OF  NATURAL  HISTORY. 


BOTANY  VOL.  IV,  PLATE  IX. 


2$  26 


29  30 


FRUITS  OF  XANTHIUM     (Natural  Size) 


ilBSARY 

UNIVERSE  OF  ILLINOIS 
URBANA 


THE  LIBRARY  OF  THE 
JUL241943 


UNIVERSITY  OF 

PLATE  X. 
X.  oviforme  Walk1. 

F.  I.    Suksdorf  (Hb.  Field  211249,  cotype  of  X.  silphiifolium  Greene). 
F.  2  and  3.   Suksdorf  189  (Hb.  Gray,  topotype  of  X.  silphiifolium  Greene). 
X.  speciosum  Kearn. 

F.  4  and  6.   Bush  1185  (Hb.  Mo.  85380,  type  material  of  X.  bubalocarpon 

Bush). 

F.  5.  Kearney  785  (Hb.  N.  Y.;  cotype). 
X.  campestre  Greene. 

F.  7.   Greene  (Hb.  Greene  19837,  type;  an  atypic  bur  on  lower  part  of  plant; 

burs  higher  up  on  type  are  more  as  in  f.  8). 
F.  8.   Heller  11629  (Hb.  Gray,  topotype). 


FIELD  MUSEUM  OF  NATURAL  HISTORY. 


BOTANY  VOL.  IV,  PLATE  X 


FRUITS  OF  XANTHIUM     (Natural  size 


FIELD   MUSEUM  OF  NATURAL  HISTORY. 


BOTANY  VOL.  IV,  PLATE  XI. 


XANTHIUM  CURVESCENS 


LIBRARY 
UNIVERSITY  OF  ILLINOIS 

URBAN A 


FIELD   MUSEUM   OF  NATURAL  HISTORY. 


BOTANY  VOL.  IV,  PLATE  XII. 


NEGATIVE 
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REVISION    OF    XANTHIUM. 


•J  PHI. I   WsrAK*    ' 

PLANTS  OK  THE  PACIFIC  COAST 


XANTHIUM  CALVUM 


LIBRARY 

UNIVERSITY  OF  ILLINOIS 
URBAN& 


FIELD  MUSEUM  OF  NATURAL  HISTORY. 


BOTANY  VOL.  IV,  PLATE  XIII. 


XANTHIUM  AUSTRALE 


OF  ILLINOIS 
URBANE 


